diff --git a/CadRevealComposer.Tests/BoundingBoxTests.cs b/CadRevealComposer.Tests/BoundingBoxTests.cs
index 3a371ec3..101b274f 100644
--- a/CadRevealComposer.Tests/BoundingBoxTests.cs
+++ b/CadRevealComposer.Tests/BoundingBoxTests.cs
@@ -2,8 +2,6 @@ namespace CadRevealComposer.Tests;
 
 using System.Drawing;
 using System.Numerics;
-using Primitives;
-using Tessellation;
 
 public class BoundingBoxTests
 {
@@ -68,4 +66,12 @@ public void Extents_ReturnsSizeInAllDimensions()
         var extents = new Vector3(3, 3, 3);
         Assert.That(boundingBox.Extents, Is.EqualTo(extents));
     }
+
+    [Test]
+    public void Volume_CalculatesCorrectVolume()
+    {
+        var boundingBox = new BoundingBox(new Vector3(1, 2, 3), new Vector3(4, 6, 8));
+        const float expectedVolume = 3 * 4 * 5; // Extents.X * Extents.Y * Extents.Z
+        Assert.That(boundingBox.Volume, Is.EqualTo(expectedVolume));
+    }
 }
diff --git a/CadRevealComposer/CadRevealNode.cs b/CadRevealComposer/CadRevealNode.cs
index 75c04513..af77bb17 100644
--- a/CadRevealComposer/CadRevealNode.cs
+++ b/CadRevealComposer/CadRevealNode.cs
@@ -5,7 +5,6 @@ namespace CadRevealComposer;
 using System.Numerics;
 using Primitives;
 using ProtoBuf;
-using Tessellation;
 using Utils;
 
 [ProtoContract(SkipConstructor = true)]
@@ -29,6 +28,12 @@ public record BoundingBox([property: ProtoMember(1)] Vector3 Min, [property: Pro
     /// </summary>
     public Vector3 Extents => (Max - Min);
 
+    /// <summary>
+    /// The Volume of the bounding box
+    /// Expressed as Extents.X * Extents.Y * Extents.Z
+    /// </summary>
+    public float Volume => Extents.X * Extents.Y * Extents.Z;
+
     /// <summary>
     /// Combine two bounds
     /// </summary>
diff --git a/CadRevealComposer/Operations/SectorSplitting/PrioritySplittingUtils.cs b/CadRevealComposer/Operations/SectorSplitting/PrioritySplittingUtils.cs
index ab5849ed..a82c020b 100644
--- a/CadRevealComposer/Operations/SectorSplitting/PrioritySplittingUtils.cs
+++ b/CadRevealComposer/Operations/SectorSplitting/PrioritySplittingUtils.cs
@@ -11,7 +11,7 @@ public static class PrioritySplittingUtils
     /// <summary>
     /// These disciplines have limited amount of data and high highlighting value.
     /// </summary>
-    private static readonly string[] PrioritizedDisciplines = ["PIPE", "ELEC", "SAFE", "INST", "TELE"];
+    private static readonly string[] PrioritizedDisciplines = ["PIPE", "ELEC", "SAFE", "INST", "TELE", "MECH"];
 
     public static void SetPriorityForPrioritySplittingWithMutation(IReadOnlyList<CadRevealNode> nodes)
     {
@@ -48,10 +48,30 @@ private static void SetPriorityOnNodesAndChildren(IEnumerable<CadRevealNode> nod
     {
         foreach (var node in nodes)
         {
-            var allChildren = CadRevealNode.GetAllNodesFlat(node);
-            foreach (var child in allChildren)
+            var allChildren = CadRevealNode.GetAllNodesFlat(node).ToList();
+
+            if (node.Attributes["Discipline"] == "MECH" && allChildren.Count > 10)
+            {
+                // This code assumes the nodes that get here are "Tag" nodes.
+                // Prioritize the largest geometries, to avoid the priority sector being too large
+                var geometriesToPrioritize = allChildren
+                    .SelectMany(childNode => childNode.Geometries.Select(primitive => (childNode, primitive)))
+                    .OrderByDescending(nx => nx.primitive.AxisAlignedBoundingBox.Volume) // Volume here is arbitrary. It will prioritize diagonal "beams". But may be better than just "Diagonal"?
+                    .Take((int)Math.Clamp(allChildren.Count * 0.4f, min: 5, max: 100)); // Arbitrary values
+
+                foreach ((CadRevealNode childNode, APrimitive primitive) in geometriesToPrioritize)
+                {
+                    childNode.Geometries = childNode
+                        .Geometries.Select(g => g == primitive ? g with { Priority = 1 } : g)
+                        .ToArray();
+                }
+            }
+            else
             {
-                child.Geometries = child.Geometries.Select(g => g with { Priority = 1 }).ToArray();
+                foreach (var child in allChildren)
+                {
+                    child.Geometries = child.Geometries.Select(g => g with { Priority = 1 }).ToArray();
+                }
             }
         }
     }