How to finish knife plunge lines with Cratex points

Plunge lines punish sloppy finishing. A belt can erase geometry fast, and sandpaper wrapped around a stick often rounds the shoulder before it removes the scratch. Cratex points give knife makers a controlled middle step: shaped rubber abrasives on a rotary tool that can reach the ricasso, plunge line, choil, and guard transition without going back to the grinder.

Why plunge lines are hard to finish

• The shoulder is small, visible, and easy to round over.
• Deep scratches near the ricasso tend to survive broad sanding passes.
• Belts remove material quickly but can change the line.
• Hand sanding is controlled but slow and awkward inside the radius.

Before choosing a point, review the Cratex grit guide.

Best Cratex shapes for plunge lines

Bullet points are best for concave plunge transitions, tight shoulders, and inside corners. Shop Cratex Points.

Cylinder points help when you need a flatter contact patch near the ricasso or choil. Shop Cratex Points.

Small wheels are useful for blending just outside the plunge line on blade flats. Shop Cratex Small Wheels.

Mandrels are required for unmounted points and wheels in Dremel, Foredom, and flex-shaft tools. Shop Cratex Mandrels.

Grit progression

1. Coarse: only for tool marks or real geometry cleanup. Stop before you change the plunge shape.
2. Medium: the safest starting point for most post-grind cleanup.
3. Fine: blends the medium scratch pattern and prepares for final sanding or polish.
4. Extra Fine: final refinement around the shoulder before hand finishing or compound.

If you are not sure where to start, start one grit finer than your ego wants. You can always step coarser; you cannot un-round a plunge line.

Step-by-step workflow

1. Tape off finished or near-finished blade surfaces.
2. Mount the point securely on a compatible mandrel.
3. Run the rotary tool at controlled speed; do not bear down.
4. Work with short passes, following the line instead of trying to force it straight.
5. Clean between grits so old abrasive does not contaminate finer passes.
6. Stop and inspect under bright side light before moving finer.
7. Finish the surrounding blade flat with small wheels or hand sanding so the scratch pattern matches.

What to avoid

• Do not use a point like a milling cutter.
• Do not chase one scratch until the plunge line changes shape.
• Do not jump from coarse straight to extra fine.
• Do not let the mandrel or shank touch the blade.
• Do not polish a wavy line; fix the geometry first.

Start with the right kit

Cleaning up plunge lines? Start with the Plunge Line Perfection Kit if you want the points, wheels, and mandrels in one box, or buy Cratex Points plus Cratex Mandrels if you already know your grit progression.

Related guides: Tool compatibility and mirror finish workflow.