feat(storage): record material grade on server nests and pick it in Nest Info

Nest records gain a materialGrade field (server schema v8, blank for existing
rows) that is searched, sorted and versioned like the other metadata. The
Nest Info dialog gets a grade picker listing the machine configs' grades for
the chosen material; density survives only an unchanged name and grade. A
blank recorded grade keeps the archive's grade while the name matches, so
records saved before v8 do not lose it on open. Saved Nests shows a Grade column.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

OpenNest.Data/NestMaterialSelection.cs

@@ -1,25 +1,48 @@
 namespace OpenNest.Data;
 
 /// <summary>
-/// Chooses the nest material when the Nest Info dialog is accepted. The dialog
-/// edits only the material name, so grade and density must come from the
-/// material the nest already has.
+/// Chooses the nest material from a material name and grade, as edited in the
+/// Nest Info dialog or recorded on the nest server. Density is not edited, so it
+/// must come from the material the nest already has.
 /// </summary>
 public static class NestMaterialSelection
 {
     /// <summary>
-    /// Returns a new material named <paramref name="selectedName"/>. When that
-    /// name matches the current material's name by <see cref="SharedListNames.Key"/>,
-    /// the current grade and density are kept; any other name gets a name-only
-    /// material. The current material is never modified or returned.
+    /// Returns a new material named <paramref name="selectedName"/> with grade
+    /// <paramref name="selectedGrade"/>. When both match the current material by
+    /// <see cref="SharedListNames.Key"/>, the current density is kept; any other
+    /// name or grade gets no density. The current material is never modified or returned.
     /// </summary>
-    public static Material Apply(Material? current, string? selectedName)
+    public static Material Apply(Material? current, string? selectedName, string? selectedGrade)
     {
         var name = selectedName ?? "";
+        var grade = selectedGrade ?? "";
 
-        if (current != null && SharedListNames.Key(current.Name) == SharedListNames.Key(name))
-            return new Material(name, current.Grade, current.Density);
+        if (
+            current != null
+            && SharedListNames.Key(current.Name) == SharedListNames.Key(name)
+            && SharedListNames.Key(current.Grade) == SharedListNames.Key(grade)
+        )
+            return new Material(name, grade, current.Density);
 
-        return new Material(name);
+        return new Material(name, grade);
+    }
+
+    /// <summary>
+    /// Applies server metadata to an archived material. A blank recorded grade means
+    /// the record predates grades, so the archive's grade stands while the name is
+    /// unchanged; every edit rewrites the archive too, so a cleared grade is blank there as well.
+    /// </summary>
+    public static Material ApplyRecorded(Material? current, string? recordedName, string? recordedGrade)
+    {
+        var grade = recordedGrade ?? "";
+        if (
+            grade.Length == 0
+            && current != null
+            && SharedListNames.Key(current.Name) == SharedListNames.Key(recordedName)
+        )
+            grade = current.Grade ?? "";
+
+        return Apply(current, recordedName, grade);
     }
 }

OpenNest.Data/NestQuery.cs

@@ -11,7 +11,7 @@ public sealed class NestQuery
     public const int MaxSearchLength = 200;
 
     /// <summary>
-    /// Case-insensitive substring matched against name, customer, material, made by,
+    /// Case-insensitive substring matched against name, customer, material, grade, made by,
     /// comments and status (stored and display names). Blank means no filter.
     /// </summary>
     public string Search { get; init; } = "";

OpenNest.Data/NestRecord.cs

@@ -29,6 +29,9 @@ public sealed class NestRecord
 
     public string Material { get; set; } = "";
 
+    /// <summary>Material grade; blank when none was chosen or the server predates grades.</summary>
+    public string MaterialGrade { get; set; } = "";
+
     public double Thickness { get; set; }
 
     /// <summary>quote | toBeCut | hasBeenCut (camelCase on the wire, case-insensitive readers).</summary>

OpenNest.Data/NestRecordFactory.cs

@@ -21,7 +21,7 @@ public static class NestRecordFactory
         nest.MadeBy = record.MadeBy;
         nest.DateLastModified = record.DateModified;
         nest.DateCreated = record.DateCreated;
-        nest.Material = NestMaterialSelection.Apply(nest.Material, record.Material);
+        nest.Material = NestMaterialSelection.ApplyRecorded(nest.Material, record.Material, record.MaterialGrade);
         nest.Thickness = record.Thickness;
     }
 
@@ -44,6 +44,7 @@ public static class NestRecordFactory
             DateCreated = nest.DateCreated,
             DateModified = nest.DateLastModified,
             Material = nest.Material?.Name ?? "",
+            MaterialGrade = nest.Material?.Grade ?? "",
             Thickness = nest.Thickness,
             Status = nest.Status,
             // The trailing empty plate is the editor's new-plate slot, not a plate of the nest.

OpenNest.Data/NestSaveSession.cs

@@ -127,7 +127,7 @@ public sealed class NestSaveSession
 
     private static bool SameEditableMetadata(NestRecord a, NestRecord b) =>
         a.Name == b.Name && a.Customer == b.Customer && a.DateCreated == b.DateCreated
-        && a.DateModified == b.DateModified && a.Material == b.Material && a.Thickness == b.Thickness
-        && a.Status == b.Status && a.PlateCount == b.PlateCount && a.PartCount == b.PartCount
+        && a.DateModified == b.DateModified && a.Material == b.Material && a.MaterialGrade == b.MaterialGrade
+        && a.Thickness == b.Thickness && a.Status == b.Status && a.PlateCount == b.PlateCount && a.PartCount == b.PartCount
         && a.Comments == b.Comments && a.MadeBy == b.MadeBy;
 }

OpenNest.Data/NestSortField.cs

@@ -16,4 +16,5 @@ public enum NestSortField
     MadeBy,
     Comments,
     FileSize,
+    MaterialGrade,
 }

OpenNest.Server.Tests/DrawingLibraryDatabaseTests.cs

@@ -21,7 +21,7 @@ public sealed class DrawingLibraryDatabaseTests
             using (var database = new NestDatabase(factory.DatabasePath, pooling: false))
                 Assert.Empty(database.QueryDrawings(new DrawingLibraryQuery { IncludeArchived = true }).Items);
             Assert.Equal(before, NestDigest(factory.DatabasePath));
-            Assert.Equal(7L, Scalar(factory.DatabasePath, "PRAGMA user_version"));
+            Assert.Equal(8L, Scalar(factory.DatabasePath, "PRAGMA user_version"));
         }
 
         using var upgraded = new NestDatabase(factory.DatabasePath, pooling: false);
@@ -42,7 +42,7 @@ public sealed class DrawingLibraryDatabaseTests
 
         using (var database = new NestDatabase(factory.DatabasePath, pooling: false))
         {
-            Assert.Equal(7L, Scalar(factory.DatabasePath, "PRAGMA user_version"));
+            Assert.Equal(8L, Scalar(factory.DatabasePath, "PRAGMA user_version"));
             Assert.Equal(before, NestDigest(factory.DatabasePath));
             // Two distinct blobs across four revisions: the bracket's notes edit and the
             // plate both reuse the bracket's first package.
@@ -79,7 +79,7 @@ public sealed class DrawingLibraryDatabaseTests
     {
         using var factory = new ServerFactory();
         using (new NestDatabase(factory.DatabasePath, pooling: false)) { }
-        Execute(factory.DatabasePath, "PRAGMA user_version=8");
+        Execute(factory.DatabasePath, "PRAGMA user_version=9");
 
         Assert.Throws<InvalidOperationException>(() => new NestDatabase(factory.DatabasePath, pooling: false));
     }

OpenNest.Server.Tests/DrawingSetDatabaseTests.cs

@@ -22,7 +22,7 @@ public sealed class DrawingSetDatabaseTests
             using (var database = new NestDatabase(factory.DatabasePath, pooling: false))
                 Assert.Empty(database.QueryDrawingSets(new DrawingSetQuery { IncludeArchived = true }).Items);
             Assert.Equal(before, Digest(factory.DatabasePath));
-            Assert.Equal(7L, Scalar(factory.DatabasePath, "PRAGMA user_version"));
+            Assert.Equal(8L, Scalar(factory.DatabasePath, "PRAGMA user_version"));
         }
 
         using var upgraded = new NestDatabase(factory.DatabasePath, pooling: false);
@@ -47,7 +47,7 @@ public sealed class DrawingSetDatabaseTests
         Assert.Equal(before, Digest(factory.DatabasePath));
         Execute(factory.DatabasePath, "DROP TABLE ix_drawing_set_members_drawing");
         using var database = new NestDatabase(factory.DatabasePath, pooling: false);
-        Assert.Equal(7L, Scalar(factory.DatabasePath, "PRAGMA user_version"));
+        Assert.Equal(8L, Scalar(factory.DatabasePath, "PRAGMA user_version"));
     }
 
     [Fact]

OpenNest.Server.Tests/NestMaterialGradeTests.cs

@@ -0,0 +1,106 @@
+using Microsoft.Data.Sqlite;
+using OpenNest.Data;
+
+namespace OpenNest.Server.Tests;
+
+public sealed class NestMaterialGradeTests
+{
+    [Fact]
+    public void Grade_RoundTripsThroughInsertUpdateAndHistory()
+    {
+        using var factory = new ServerFactory();
+        using var database = new NestDatabase(factory.DatabasePath, pooling: false);
+        var id = Guid.NewGuid();
+
+        var created = database.Insert(id, Record("Job", "Stainless", "304"), [1]);
+        Assert.Equal("304", created.MaterialGrade);
+
+        var updated = database.UpdateMetadata(id, Record("Job", "Stainless", "316"), created.Revision)!;
+        Assert.Equal("316", updated.MaterialGrade);
+        Assert.Equal(created.Revision + 1, updated.Revision);
+
+        var history = database.History(id, 0, 10)!;
+        Assert.Equal(["316", "304"], history.Items.Select(r => r.MaterialGrade));
+    }
+
+    [Fact]
+    public void GradeOnlyChange_IsNotANoOp()
+    {
+        using var factory = new ServerFactory();
+        using var database = new NestDatabase(factory.DatabasePath, pooling: false);
+        var id = Guid.NewGuid();
+        var created = database.Insert(id, Record("Job", "Stainless", "304"), [1]);
+
+        var unchanged = database.UpdateMetadata(id, Record("Job", "Stainless", "304"), created.Revision)!;
+        var changed = database.UpdateMetadata(id, Record("Job", "Stainless", "316"), created.Revision)!;
+
+        Assert.Equal(created.Revision, unchanged.Revision);
+        Assert.Equal(created.Revision + 1, changed.Revision);
+    }
+
+    [Fact]
+    public void Query_SearchesAndSortsByGrade()
+    {
+        using var factory = new ServerFactory();
+        using var database = new NestDatabase(factory.DatabasePath, pooling: false);
+        database.Insert(Guid.NewGuid(), Record("A", "Aluminum", "6061"), [1]);
+        database.Insert(Guid.NewGuid(), Record("B", "Aluminum", "5052"), [1]);
+        database.Insert(Guid.NewGuid(), Record("C", "Stainless", "304"), [1]);
+
+        var found = database.Query(new NestQuery { Search = "5052" });
+        Assert.Equal("B", Assert.Single(found.Items).Name);
+
+        var sorted = database.Query(new NestQuery { Sort = NestSortField.MaterialGrade, Descending = false });
+        Assert.Equal(["C", "B", "A"], sorted.Items.Select(r => r.Name));
+    }
+
+    [Fact]
+    public void Version7Database_GainsBlankGradeAndKeepsRecords()
+    {
+        using var factory = new ServerFactory();
+        var id = Guid.NewGuid();
+        using (var database = new NestDatabase(factory.DatabasePath, pooling: false))
+            database.Insert(id, Record("Legacy", "Stainless", "304"), [1]);
+        Execute(factory.DatabasePath, """
+            ALTER TABLE nests DROP COLUMN materialGrade;
+            ALTER TABLE nest_revisions DROP COLUMN materialGrade;
+            PRAGMA user_version=7;
+            """);
+
+        using var upgraded = new NestDatabase(factory.DatabasePath, pooling: false);
+
+        var record = upgraded.Get(id)!;
+        Assert.Equal("Stainless", record.Material);
+        Assert.Equal("", record.MaterialGrade);
+        Assert.Equal("", Assert.Single(upgraded.History(id, 0, 10)!.Items).MaterialGrade);
+        Assert.Equal(8L, Scalar(factory.DatabasePath, "PRAGMA user_version"));
+    }
+
+    private static NestRecord Record(string name, string material, string grade) => new()
+    {
+        Name = name,
+        Material = material,
+        MaterialGrade = grade,
+        Thickness = 0.25,
+        DateCreated = new DateTime(2026, 1, 1),
+        DateModified = new DateTime(2026, 1, 2),
+    };
+
+    private static void Execute(string path, string sql)
+    {
+        using var connection = new SqliteConnection($"Data Source={path};Pooling=False");
+        connection.Open();
+        using var command = connection.CreateCommand();
+        command.CommandText = sql;
+        command.ExecuteNonQuery();
+    }
+
+    private static object? Scalar(string path, string sql)
+    {
+        using var connection = new SqliteConnection($"Data Source={path};Pooling=False");
+        connection.Open();
+        using var command = connection.CreateCommand();
+        command.CommandText = sql;
+        return command.ExecuteScalar();
+    }
+}

OpenNest.Server.Tests/NestQueryTests.cs

@@ -321,6 +321,7 @@ public sealed class NestQueryTests : IDisposable
                 DateCreated = new DateTime(2026, 1, 1 + index % 28, 8, 0, 0, DateTimeKind.Unspecified),
                 DateModified = new DateTime(2026, 1, 2 + index % 27, 9, 0, 0, DateTimeKind.Unspecified),
                 Material = index % 3 == 0 ? "Synthetic steel" : "Synthetic alloy",
+                MaterialGrade = index % 4 == 0 ? "" : $"Grade {index % 5}",
                 Thickness = 0.25 + index % 3 * 0.125,
                 Status = statuses[index % statuses.Length],
                 PlateCount = 1 + index % 4,
@@ -362,6 +363,7 @@ public sealed class NestQueryTests : IDisposable
             NestSortField.MadeBy => Text(r => r.MadeBy),
             NestSortField.Comments => Text(r => r.Comments),
             NestSortField.FileSize => (a, b) => a.FileSize.CompareTo(b.FileSize),
+            NestSortField.MaterialGrade => Text(r => r.MaterialGrade),
             _ => throw new ArgumentOutOfRangeException(nameof(field)),
         };
         var sorted = records.ToList();

OpenNest.Server/NestDatabase.cs

@@ -149,11 +149,11 @@ public sealed partial class NestDatabase : IDisposable
             command.Transaction = transaction;
             command.CommandText = """
                 INSERT INTO nests (id, name, customer, dateCreated, dateModified, material,
-                    thickness, status, plateCount, partCount, comments, madeBy, fileSize,
-                    savedAt, file)
+                    materialGrade, thickness, status, plateCount, partCount, comments, madeBy,
+                    fileSize, savedAt, file)
                 VALUES ($id, $name, $customer, $dateCreated, $dateModified, $material,
-                    $thickness, $status, $plateCount, $partCount, $comments, $madeBy,
-                    $fileSize, $savedAt, $file)
+                    $materialGrade, $thickness, $status, $plateCount, $partCount, $comments,
+                    $madeBy, $fileSize, $savedAt, $file)
                 """;
             AddRecordParameters(command, id, record, file, updateFile: true);
             command.ExecuteNonQuery();
@@ -199,7 +199,7 @@ public sealed partial class NestDatabase : IDisposable
                 UPDATE nests SET
                     name = $name, customer = $customer, dateCreated = $dateCreated,
                     dateModified = $dateModified, material = $material,
-                    thickness = $thickness, status = $status, plateCount = $plateCount,
+                    materialGrade = $materialGrade, thickness = $thickness, status = $status, plateCount = $plateCount,
                     partCount = $partCount, comments = $comments, madeBy = $madeBy,
                     savedAt = $savedAt, revision = $revision, restoredFromRevision=$source{fileClause}
                 WHERE id = $id
@@ -297,8 +297,8 @@ public sealed partial class NestDatabase : IDisposable
 
     private static bool SameMetadata(NestRecord a, NestRecord b) =>
         a.Name == b.Name && a.Customer == b.Customer && a.DateCreated == b.DateCreated &&
-        a.DateModified == b.DateModified && a.Material == b.Material && a.Thickness == b.Thickness &&
-        a.Status == b.Status && a.PlateCount == b.PlateCount && a.PartCount == b.PartCount &&
+        a.DateModified == b.DateModified && a.Material == b.Material && a.MaterialGrade == b.MaterialGrade &&
+        a.Thickness == b.Thickness && a.Status == b.Status && a.PlateCount == b.PlateCount && a.PartCount == b.PartCount &&
         a.Comments == b.Comments && a.MadeBy == b.MadeBy;
 
     private void Snapshot(Guid id, SqliteTransaction transaction)
@@ -319,7 +319,7 @@ public sealed partial class NestDatabase : IDisposable
             command.Transaction = transaction;
             command.CommandText = "PRAGMA user_version";
             var version = (long)command.ExecuteScalar()!;
-            if (version > 7) throw new InvalidOperationException("Database schema is newer than this server.");
+            if (version > 8) throw new InvalidOperationException("Database schema is newer than this server.");
             if (version == 0)
             {
                 command.CommandText = """
@@ -371,6 +371,21 @@ public sealed partial class NestDatabase : IDisposable
                 command.CommandText = DrawingSetSchema;
                 command.ExecuteNonQuery();
             }
+            if (version < 8)
+            {
+                // Existing records stay blank until saved again; clients keep the archive's grade meanwhile.
+                foreach (var table in new[] { "nests", "nest_revisions" })
+                {
+                    command.CommandText = $"SELECT COUNT(*) FROM pragma_table_info('{table}') WHERE name='materialGrade'";
+                    if ((long)command.ExecuteScalar()! == 0)
+                    {
+                        command.CommandText = $"ALTER TABLE {table} ADD COLUMN materialGrade TEXT NOT NULL DEFAULT ''";
+                        command.ExecuteNonQuery();
+                    }
+                }
+                command.CommandText = "PRAGMA user_version=8";
+                command.ExecuteNonQuery();
+            }
             transaction.Commit();
         }
     }
@@ -408,7 +423,8 @@ public sealed partial class NestDatabase : IDisposable
 
     private const string RecordColumns = """
         id, name, customer, dateCreated, dateModified, material, thickness,
-        status, plateCount, partCount, comments, madeBy, fileSize, savedAt, revision, deleted, restoredFromRevision
+        status, plateCount, partCount, comments, madeBy, fileSize, savedAt, revision, deleted, restoredFromRevision,
+        materialGrade
         """;
 
     // Case-insensitive (ASCII) substring over the text columns and the status's stored
@@ -417,6 +433,7 @@ public sealed partial class NestDatabase : IDisposable
         name LIKE $pattern ESCAPE '\'
             OR customer LIKE $pattern ESCAPE '\'
             OR material LIKE $pattern ESCAPE '\'
+            OR materialGrade LIKE $pattern ESCAPE '\'
             OR madeBy LIKE $pattern ESCAPE '\'
             OR comments LIKE $pattern ESCAPE '\'
             OR status LIKE $pattern ESCAPE '\'
@@ -440,6 +457,7 @@ public sealed partial class NestDatabase : IDisposable
         NestSortField.MadeBy => "madeBy COLLATE NOCASE",
         NestSortField.Comments => "comments COLLATE NOCASE",
         NestSortField.FileSize => "fileSize",
+        NestSortField.MaterialGrade => "materialGrade COLLATE NOCASE",
         _ => throw new ArgumentOutOfRangeException(nameof(field), field, "Unsupported sort column."),
     };
 
@@ -461,6 +479,7 @@ public sealed partial class NestDatabase : IDisposable
         command.Parameters.AddWithValue("$dateCreated", record.DateCreated.ToString("o"));
         command.Parameters.AddWithValue("$dateModified", record.DateModified.ToString("o"));
         command.Parameters.AddWithValue("$material", record.Material);
+        command.Parameters.AddWithValue("$materialGrade", record.MaterialGrade);
         command.Parameters.AddWithValue("$thickness", record.Thickness);
         command.Parameters.AddWithValue("$status", record.Status.ToString());
         command.Parameters.AddWithValue("$plateCount", record.PlateCount);
@@ -498,6 +517,7 @@ public sealed partial class NestDatabase : IDisposable
             Revision = reader.GetInt32(first + 14),
             Deleted = reader.GetInt32(first + 15) != 0,
             RestoredFromRevision = reader.IsDBNull(first + 16) ? null : reader.GetInt32(first + 16),
+            MaterialGrade = reader.GetString(first + 17),
         };
     }
 }

OpenNest.Server/NestMetadata.cs

@@ -51,6 +51,7 @@ internal static class NestMetadata
         if (record.Name is null) return "name must be a string.";
         if (record.Customer is null) return "customer must be a string.";
         if (record.Material is null) return "material must be a string.";
+        if (record.MaterialGrade is null) return "materialGrade must be a string.";
         if (record.Comments is null) return "comments must be a string.";
         if (record.MadeBy is null) return "madeBy must be a string.";
         if (!Enum.IsDefined(record.Status)) return "status must be draft, quote, toBeCut or hasBeenCut.";

OpenNest.Tests/Data/NestMaterialSelectionTests.cs

@@ -5,11 +5,11 @@ namespace OpenNest.Tests.Data;
 public class NestMaterialSelectionTests
 {
     [Fact]
-    public void Apply_UnchangedName_KeepsGradeAndDensity()
+    public void Apply_UnchangedNameAndGrade_KeepsDensity()
     {
         var current = new Material("Stainless", "304", 0.289);
 
-        var result = NestMaterialSelection.Apply(current, "Stainless");
+        var result = NestMaterialSelection.Apply(current, "Stainless", "304");
 
         Assert.Equal("Stainless", result.Name);
         Assert.Equal("304", result.Grade);
@@ -21,7 +21,7 @@ public class NestMaterialSelectionTests
     {
         var current = new Material("Cold Rolled Steel", "1008", 0.284);
 
-        var result = NestMaterialSelection.Apply(current, " cold  rolled\tsteel ");
+        var result = NestMaterialSelection.Apply(current, " cold  rolled\tsteel ", "1008");
 
         Assert.Equal(" cold  rolled\tsteel ", result.Name);
         Assert.Equal("1008", result.Grade);
@@ -33,7 +33,7 @@ public class NestMaterialSelectionTests
     {
         var current = new Material("Stainless", "304", 0.289);
 
-        var result = NestMaterialSelection.Apply(current, "Aluminum");
+        var result = NestMaterialSelection.Apply(current, "Aluminum", "");
 
         Assert.Equal("Aluminum", result.Name);
         Assert.True(string.IsNullOrEmpty(result.Grade));
@@ -45,7 +45,7 @@ public class NestMaterialSelectionTests
     {
         var current = new Material("Stainless", "304", 0.289);
 
-        var result = NestMaterialSelection.Apply(current, "");
+        var result = NestMaterialSelection.Apply(current, "", "");
 
         Assert.Equal("", result.Name);
         Assert.True(string.IsNullOrEmpty(result.Grade));
@@ -55,7 +55,7 @@ public class NestMaterialSelectionTests
     [Fact]
     public void Apply_NoCurrentMaterial_GetsNameOnly()
     {
-        var result = NestMaterialSelection.Apply(null, "Stainless");
+        var result = NestMaterialSelection.Apply(null, "Stainless", null);
 
         Assert.Equal("Stainless", result.Name);
         Assert.True(string.IsNullOrEmpty(result.Grade));
@@ -67,7 +67,7 @@ public class NestMaterialSelectionTests
     {
         var current = new Material("Stainless", "304", 0.289);
 
-        var result = NestMaterialSelection.Apply(current, "stainless");
+        var result = NestMaterialSelection.Apply(current, "stainless", "304");
         result.Grade = "316";
         result.Density = 1;
 
@@ -77,6 +77,67 @@ public class NestMaterialSelectionTests
         Assert.Equal(0.289, current.Density);
     }
 
+    [Fact]
+    public void Apply_ChangedGrade_TakesGradeWithoutDensity()
+    {
+        var current = new Material("Stainless", "304", 0.289);
+
+        var result = NestMaterialSelection.Apply(current, "Stainless", "316");
+
+        Assert.Equal("Stainless", result.Name);
+        Assert.Equal("316", result.Grade);
+        Assert.Equal(0, result.Density);
+    }
+
+    [Fact]
+    public void Apply_ChangedNameWithGrade_TakesNameAndGrade()
+    {
+        var current = new Material("Stainless", "304", 0.289);
+
+        var result = NestMaterialSelection.Apply(current, "Aluminum", "5052");
+
+        Assert.Equal("Aluminum", result.Name);
+        Assert.Equal("5052", result.Grade);
+        Assert.Equal(0, result.Density);
+    }
+
+    [Theory]
+    [InlineData("")]
+    [InlineData(null)]
+    public void ApplyRecorded_BlankGradeWithSameName_KeepsArchivedGradeAndDensity(string? recordedGrade)
+    {
+        var current = new Material("Stainless", "304", 0.289);
+
+        var result = NestMaterialSelection.ApplyRecorded(current, "stainless", recordedGrade);
+
+        Assert.Equal("stainless", result.Name);
+        Assert.Equal("304", result.Grade);
+        Assert.Equal(0.289, result.Density);
+    }
+
+    [Fact]
+    public void ApplyRecorded_BlankGradeWithChangedName_GetsNameOnly()
+    {
+        var current = new Material("Stainless", "304", 0.289);
+
+        var result = NestMaterialSelection.ApplyRecorded(current, "Aluminum", "");
+
+        Assert.Equal("Aluminum", result.Name);
+        Assert.Equal("", result.Grade);
+        Assert.Equal(0, result.Density);
+    }
+
+    [Fact]
+    public void ApplyRecorded_RecordedGrade_Wins()
+    {
+        var current = new Material("Stainless", "304", 0.289);
+
+        var result = NestMaterialSelection.ApplyRecorded(current, "Stainless", "316");
+
+        Assert.Equal("316", result.Grade);
+        Assert.Equal(0, result.Density);
+    }
+
     [Theory]
     [InlineData("Carbon Steel", "CARBON STEEL")]
     [InlineData("  carbon \t steel\n", "CARBON STEEL")]

OpenNest.Tests/Data/NestRecordFactoryTests.cs

@@ -34,6 +34,7 @@ public class NestRecordFactoryTests
         NestRecordFactory.ApplyMetadata(nest, current);
         var roundTrip = NestRecordFactory.FromNest(nest, Guid.Empty, 0);
         Assert.Equal(current.Material, roundTrip.Material);
+        Assert.Equal(sameMaterial ? "Test grade" : "", roundTrip.MaterialGrade);
         Assert.Equal(current.Thickness, roundTrip.Thickness);
         Assert.Equal(current.DateCreated, roundTrip.DateCreated);
         Assert.Equal(current.DateModified, roundTrip.DateModified);
@@ -58,7 +59,7 @@ public class NestRecordFactoryTests
         var nest = new Nest("Job 42")
         {
             Customer = "Cozy Cat",
-            Material = new Material("Aluminum"),
+            Material = new Material("Aluminum", "5052"),
             Thickness = 0.125,
             Status = NestStatus.ToBeCut,
             MadeBy = "AJ",
@@ -89,6 +90,7 @@ public class NestRecordFactoryTests
         Assert.Equal("Job 42", record.Name);
         Assert.Equal("Cozy Cat", record.Customer);
         Assert.Equal("Aluminum", record.Material);
+        Assert.Equal("5052", record.MaterialGrade);
         Assert.Equal(0.125, record.Thickness);
         Assert.Equal(NestStatus.ToBeCut, record.Status);
         Assert.Equal("AJ", record.MadeBy);
@@ -111,6 +113,7 @@ public class NestRecordFactoryTests
         Assert.Equal(0, record.PlateCount);
         Assert.Equal(0, record.PartCount);
         Assert.Equal("", record.Material);
+        Assert.Equal("", record.MaterialGrade);
         Assert.Equal("", record.Comments);
         Assert.Equal("", record.MadeBy);
     }

OpenNest.WinForms.Tests/Forms/EditNestInfoFormTests.cs

@@ -216,6 +216,56 @@ public class EditNestInfoFormTests
         });
     }
 
+    [Fact]
+    public void GradeList_FollowsMaterial_AndSavesChosenGrade()
+    {
+        RunSta(() =>
+        {
+            var nest = new Nest { Material = new Material("Stainless", "304", 0.289) };
+            using var form = new EditNestInfoForm();
+            form.SetMaterialCatalog(new[]
+            {
+                new Data.MaterialConfig { Name = "Stainless", Grade = "316" },
+                new Data.MaterialConfig { Name = "Stainless", Grade = "304" },
+                new Data.MaterialConfig { Name = "Aluminum", Grade = "5052" },
+            });
+            form.LoadNestInfo(nest);
+            var gradeBox = Assert.IsType<ComboBox>(form.Controls.Find("gradeBox", true).Single());
+
+            Assert.Equal(new[] { "304", "316" }, gradeBox.Items.Cast<string>());
+            Assert.Equal("304", form.MaterialGrade);
+
+            form.MaterialName = "aluminum";
+            Assert.Equal(new[] { "5052" }, gradeBox.Items.Cast<string>());
+            Assert.Equal("", form.MaterialGrade);
+
+            form.MaterialGrade = "5052";
+            form.SaveNestInfo(nest);
+
+            Assert.Equal("Aluminum", nest.Material.Name);
+            Assert.Equal("5052", nest.Material.Grade);
+            Assert.Equal(0, nest.Material.Density);
+        });
+    }
+
+    [Fact]
+    public void SaveWithChangedGrade_KeepsNameAndDropsDensity()
+    {
+        RunSta(() =>
+        {
+            var nest = new Nest { Material = new Material("Stainless", "304", 0.289) };
+            using var form = new EditNestInfoForm();
+            form.LoadNestInfo(nest);
+            form.MaterialGrade = "316";
+
+            form.SaveNestInfo(nest);
+
+            Assert.Equal("Stainless", nest.Material.Name);
+            Assert.Equal("316", nest.Material.Grade);
+            Assert.Equal(0, nest.Material.Density);
+        });
+    }
+
     private static void RunSta(Action action) =>
         StaTestThread.Run(action, TimeSpan.FromSeconds(15), "The STA test did not complete.");
 }

OpenNest/Forms/EditNestForm.cs

@@ -758,6 +758,7 @@ namespace OpenNest.Forms
         public async Task ShowNestInfoEditorAsync()
         {
             var form = new EditNestInfoForm { AllowRename = NestStorage.Settings.IsDatabaseMode };
+            form.SetMaterialCatalog(MachineSettings.LoadMaterials());
             form.LoadNestInfo(Nest);
             _ = ShowReleaseOriginAsync(form);
 

OpenNest/Forms/EditNestInfoForm.Designer.cs

@@ -64,6 +64,8 @@
             this.label5 = new System.Windows.Forms.Label();
             this.labelMaterial = new System.Windows.Forms.Label();
             this.materialBox = new System.Windows.Forms.ComboBox();
+            this.labelGrade = new System.Windows.Forms.Label();
+            this.gradeBox = new System.Windows.Forms.ComboBox();
             this.labelStatus = new System.Windows.Forms.Label();
             this.statusBox = new System.Windows.Forms.ComboBox();
             this.labelMadeBy = new System.Windows.Forms.Label();
@@ -408,37 +410,40 @@
             this.tableLayoutPanel3.ColumnCount = 2;
             this.tableLayoutPanel3.ColumnStyles.Add(new System.Windows.Forms.ColumnStyle());
             this.tableLayoutPanel3.ColumnStyles.Add(new System.Windows.Forms.ColumnStyle(System.Windows.Forms.SizeType.Percent, 100F));
-            this.tableLayoutPanel3.Controls.Add(this.tableLayoutPanel4, 1, 6);
+            this.tableLayoutPanel3.Controls.Add(this.tableLayoutPanel4, 1, 7);
             this.tableLayoutPanel3.Controls.Add(this.label1, 0, 0);
             this.tableLayoutPanel3.Controls.Add(this.nameBox, 1, 0);
-            this.tableLayoutPanel3.Controls.Add(this.label2, 0, 5);
+            this.tableLayoutPanel3.Controls.Add(this.label2, 0, 6);
             this.tableLayoutPanel3.Controls.Add(this.labelThk, 0, 3);
             this.tableLayoutPanel3.Controls.Add(this.thicknessBox, 1, 3);
             this.tableLayoutPanel3.Controls.Add(this.labelMaterial, 0, 4);
             this.tableLayoutPanel3.Controls.Add(this.materialBox, 1, 4);
+            this.tableLayoutPanel3.Controls.Add(this.labelGrade, 0, 5);
+            this.tableLayoutPanel3.Controls.Add(this.gradeBox, 1, 5);
             this.tableLayoutPanel3.Controls.Add(this.label3, 0, 1);
             this.tableLayoutPanel3.Controls.Add(this.label4, 0, 2);
-            this.tableLayoutPanel3.Controls.Add(this.customerBox, 1, 5);
+            this.tableLayoutPanel3.Controls.Add(this.customerBox, 1, 6);
             this.tableLayoutPanel3.Controls.Add(this.textBox1, 1, 1);
             this.tableLayoutPanel3.Controls.Add(this.textBox2, 1, 2);
-            this.tableLayoutPanel3.Controls.Add(this.label5, 0, 6);
-            this.tableLayoutPanel3.Controls.Add(this.labelStatus, 0, 7);
-            this.tableLayoutPanel3.Controls.Add(this.statusBox, 1, 7);
-            this.tableLayoutPanel3.Controls.Add(this.labelMadeBy, 0, 8);
-            this.tableLayoutPanel3.Controls.Add(this.madeByBox, 1, 8);
+            this.tableLayoutPanel3.Controls.Add(this.label5, 0, 7);
+            this.tableLayoutPanel3.Controls.Add(this.labelStatus, 0, 8);
+            this.tableLayoutPanel3.Controls.Add(this.statusBox, 1, 8);
+            this.tableLayoutPanel3.Controls.Add(this.labelMadeBy, 0, 9);
+            this.tableLayoutPanel3.Controls.Add(this.madeByBox, 1, 9);
             this.tableLayoutPanel3.Location = new System.Drawing.Point(6, 6);
             this.tableLayoutPanel3.Name = "tableLayoutPanel3";
-            this.tableLayoutPanel3.RowCount = 9;
-            this.tableLayoutPanel3.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 11.11111F));
-            this.tableLayoutPanel3.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 11.11111F));
-            this.tableLayoutPanel3.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 11.11111F));
-            this.tableLayoutPanel3.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 11.11111F));
-            this.tableLayoutPanel3.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 11.11111F));
-            this.tableLayoutPanel3.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 11.11111F));
-            this.tableLayoutPanel3.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 11.11111F));
-            this.tableLayoutPanel3.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 11.11111F));
-            this.tableLayoutPanel3.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 11.11111F));
-            this.tableLayoutPanel3.Size = new System.Drawing.Size(362, 280);
+            this.tableLayoutPanel3.RowCount = 10;
+            this.tableLayoutPanel3.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 10F));
+            this.tableLayoutPanel3.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 10F));
+            this.tableLayoutPanel3.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 10F));
+            this.tableLayoutPanel3.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 10F));
+            this.tableLayoutPanel3.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 10F));
+            this.tableLayoutPanel3.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 10F));
+            this.tableLayoutPanel3.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 10F));
+            this.tableLayoutPanel3.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 10F));
+            this.tableLayoutPanel3.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 10F));
+            this.tableLayoutPanel3.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 10F));
+            this.tableLayoutPanel3.Size = new System.Drawing.Size(362, 311);
             this.tableLayoutPanel3.TabIndex = 0;
             // 
             // tableLayoutPanel4
@@ -532,6 +537,22 @@
             this.materialBox.Name = "materialBox";
             this.materialBox.Size = new System.Drawing.Size(224, 24);
             this.materialBox.TabIndex = 11;
+            //
+            // labelGrade
+            //
+            this.labelGrade.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Left | System.Windows.Forms.AnchorStyles.Right)));
+            this.labelGrade.AutoSize = true;
+            this.labelGrade.Name = "labelGrade";
+            this.labelGrade.TabIndex = 10;
+            this.labelGrade.Text = "Grade :";
+            //
+            // gradeBox
+            //
+            this.gradeBox.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Left | System.Windows.Forms.AnchorStyles.Right)));
+            this.gradeBox.FormattingEnabled = true;
+            this.gradeBox.Name = "gradeBox";
+            this.gradeBox.Size = new System.Drawing.Size(224, 24);
+            this.gradeBox.TabIndex = 11;
             // 
             // labelStatus
             // 
@@ -786,6 +807,8 @@
         private System.Windows.Forms.Label label5;
         private System.Windows.Forms.Label labelMaterial;
         private System.Windows.Forms.ComboBox materialBox;
+        private System.Windows.Forms.Label labelGrade;
+        private System.Windows.Forms.ComboBox gradeBox;
         private System.Windows.Forms.Label labelStatus;
         private System.Windows.Forms.ComboBox statusBox;
         private System.Windows.Forms.Label labelMadeBy;

OpenNest/Forms/EditNestInfoForm.cs

@@ -1,4 +1,6 @@
 using System;
+using System.Collections.Generic;
+using System.Linq;
 using System.Windows.Forms;
 using OpenNest.Data;
 using OpenNest.Geometry;
@@ -11,6 +13,8 @@ namespace OpenNest.Forms
         private readonly Timer timer;
         private DateTime dateCreated;
         private DateTime dateLastModified;
+        private List<MaterialConfig> materialCatalog = new();
+        private string gradeMaterialKey = "";
 
         public EditNestInfoForm()
         {
@@ -34,6 +38,7 @@ namespace OpenNest.Forms
             };
             Disposed += (sender, e) => timer.Dispose();
             nameBox.TextChanged += (sender, e) => EnableCheck();
+            materialBox.TextChanged += (sender, e) => RefreshGrades();
             EnableCheck();
         }
 
@@ -142,6 +147,57 @@ namespace OpenNest.Forms
             set { materialBox.Text = value; }
         }
 
+        public string MaterialGrade
+        {
+            get { return gradeBox.Text; }
+            set { gradeBox.Text = value; }
+        }
+
+        /// <summary>
+        /// Offers the machine configurations' materials: their names join the material
+        /// list, and the grade list shows the grades on file for the chosen material.
+        /// </summary>
+        public void SetMaterialCatalog(IEnumerable<MaterialConfig> materials)
+        {
+            materialCatalog = materials.ToList();
+
+            var text = materialBox.Text;
+            var names = materialBox.Items.Cast<string>()
+                .Concat(materialCatalog.Select(m => m.Name))
+                .Where(name => !string.IsNullOrWhiteSpace(name))
+                .GroupBy(SharedListNames.Key)
+                .Select(group => group.First())
+                .OrderBy(name => name, StringComparer.OrdinalIgnoreCase)
+                .ToArray();
+            materialBox.Items.Clear();
+            materialBox.Items.AddRange(names);
+            materialBox.Text = text;
+            RefreshGrades();
+        }
+
+        /// <summary>
+        /// Lists the grades on file for the typed material. A grade belongs to its
+        /// material, so changing the material clears a grade the new one does not have.
+        /// </summary>
+        private void RefreshGrades()
+        {
+            var text = gradeBox.Text;
+            var key = SharedListNames.Key(materialBox.Text);
+            var grades = materialCatalog
+                .Where(m => SharedListNames.Key(m.Name) == key && !string.IsNullOrWhiteSpace(m.Grade))
+                .Select(m => m.Grade)
+                .GroupBy(SharedListNames.Key)
+                .Select(group => group.First())
+                .OrderBy(grade => grade, StringComparer.OrdinalIgnoreCase)
+                .ToArray();
+            if (key != gradeMaterialKey && !grades.Any(grade => SharedListNames.Key(grade) == SharedListNames.Key(text)))
+                text = "";
+            gradeMaterialKey = key;
+            gradeBox.Items.Clear();
+            gradeBox.Items.AddRange(grades);
+            gradeBox.Text = text;
+        }
+
         public NestStatus Status
         {
             get { return statusBox.SelectedItem is NestStatus status ? status : NestStatus.Quote; }
@@ -245,6 +301,7 @@ namespace OpenNest.Forms
             DateLastModified = nest.DateLastModified;
             Thickness = nest.Thickness;
             MaterialName = nest.Material?.Name ?? "";
+            MaterialGrade = nest.Material?.Grade ?? "";
             Status = nest.Status;
             MadeBy = nest.MadeBy ?? "";
             SizeString = nest.PlateDefaults.Size.ToString();
@@ -267,7 +324,7 @@ namespace OpenNest.Forms
             nest.DateCreated = DateCreated;
             nest.DateLastModified = DateLastModified;
             nest.Thickness = Thickness;
-            nest.Material = NestMaterialSelection.Apply(nest.Material, MaterialName);
+            nest.Material = NestMaterialSelection.Apply(nest.Material, MaterialName, MaterialGrade);
             nest.Status = Status;
             nest.MadeBy = MadeBy;
             nest.PlateDefaults.Size = OpenNest.Geometry.Size.Parse(SizeString);

OpenNest/Forms/MachineSettings.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
+using System.Linq;
 using System.Windows.Forms;
 using OpenNest.Data;
 
@@ -42,6 +43,10 @@ namespace OpenNest.Forms
             catch (UnauthorizedAccessException) { }
             return machines;
         }
+
+        /// <summary>Every material and grade on file across the readable machine configurations.</summary>
+        public static IEnumerable<MaterialConfig> LoadMaterials() =>
+            LoadMachines().SelectMany(machine => machine.Materials);
         private static bool defaultsWarned;
 
         /// <summary>

OpenNest/Forms/SavedNestsForm.cs

@@ -111,6 +111,7 @@ public sealed class SavedNestsForm : Form
         AddNestColumn("Customer", NestSortField.Customer, 160);
         AddNestColumn("Made by", NestSortField.MadeBy, 90);
         AddNestColumn("Material", NestSortField.Material, 150);
+        AddNestColumn("Grade", NestSortField.MaterialGrade, 80);
         AddNestColumn("Thickness", NestSortField.Thickness, 80, alignRight: true);
         AddNestColumn("Created", NestSortField.DateCreated, 140);
         AddNestColumn("Saved", NestSortField.SavedAt, 140);
@@ -515,6 +516,7 @@ public sealed class SavedNestsForm : Form
                 record.Customer,
                 record.MadeBy,
                 record.Material,
+                record.MaterialGrade,
                 record.Thickness.ToString("0.####", CultureInfo.CurrentCulture),
                 FormatDate(record.DateCreated),
                 FormatDate(record.SavedAt),
@@ -816,6 +818,7 @@ public sealed class SavedNestsForm : Form
             });
             if (IsDisposed) return;
             using var dialog = new EditNestInfoForm { AllowRename = true };
+            dialog.SetMaterialCatalog(MachineSettings.LoadMaterials());
             dialog.LoadNestInfo(nest);
             while (true)
             {

docs/nest-storage.md

@@ -5,7 +5,7 @@ The desktop app can save nests two ways:
 - **File mode** (default, unchanged behavior): Save/Save As write a `.nest` ZIP
   archive to disk via the normal file dialog. See [nest-file-format.md](nest-file-format.md).
 - **Database mode**: Open browses server records 100 at a time. The Find box
-  searches name, customer, material, made by, comments and status on the server
+  searches name, customer, material, grade, made by, comments and status on the server
   after a short typing pause (Enter in the box searches at once); clicking a
   column header sorts every match on the server (click again to reverse); the
   arrow buttons move between pages and the title and find bar show the range and
@@ -77,7 +77,8 @@ so upgrade the server before desktops that can set it.
 | `name` | string | |
 | `customer` | string | |
 | `dateCreated` / `dateModified` | datetime | Set by the client from the nest's own metadata. |
-| `material` | string | |
+| `material` | string | Material name (type), e.g. `Stainless`. |
+| `materialGrade` | string | Optional; default blank. Older servers drop it. A blank grade on a record saved before schema v8 is treated as unrecorded: opening keeps the archive's grade while the material name matches. |
 | `thickness` | number | |
 | `status` | `"draft"` \| `"quote"` \| `"toBeCut"` \| `"hasBeenCut"` | Default `quote`. |
 | `plateCount` / `partCount` | integer | Computed client-side at save time (non-cutoff parts only). |
@@ -163,13 +164,13 @@ only the requested page of metadata (never archive bytes):
 - `search` (optional): trimmed, at most 200 characters, no NUL characters;
   blank means no filter.
   Case-insensitive substring of the whole text in `name`, `customer`, `material`,
-  `madeBy`, `comments` or the status (`ToBeCut` or the display name `To Be Cut`).
+  `materialGrade`, `madeBy`, `comments` or the status (`ToBeCut` or the display name `To Be Cut`).
   `%`, `_` and `\` are literal. Dates and numbers are not matched as text.
   Case folding is ASCII-only (SQLite `LIKE`).
 - `offset` (default 0, at least 0) and `limit` (default 100, 1 to 500).
 - `sort` (default `savedAt`): one of `savedAt`, `name`, `customer`, `status`,
   `material`, `dateCreated`, `dateModified`, `thickness`, `plateCount`,
-  `partCount`, `madeBy`, `comments`, `fileSize` (names, case-insensitive; no
+  `partCount`, `madeBy`, `comments`, `fileSize`, `materialGrade` (names, case-insensitive; no
   numbers). Text columns sort case-insensitively (ASCII); dates sort as their
   stored ISO text. `order` is `asc` or `desc` (default `desc`).
 - Ties are broken by `id` in the same direction, so pages partition the matches
@@ -535,6 +536,11 @@ v7 refuses to open a v7 database, so rolling back needs the pre-upgrade backup.
 The stopped-volume `tar` backup includes the set and release tables; `nest_manifest.py` and
 `restore_check` do not verify them yet.
 
+Schema v8 adds a `materialGrade` text column (default blank) to `nests` and
+`nest_revisions`; existing records keep a blank grade until they are next saved.
+A server older than v8 refuses to open a v8 database, so rolling back needs the
+pre-upgrade backup.
+
 ## Storage
 
 `OpenNest.Server.NestDatabase` uses SQLite (`Microsoft.Data.Sqlite`) with