Grinding and Sharpening 5160: Belt Recommendations & Technique

5160 is a forgiving steel on the grinder, and the challenges it does present come from the blades people make out of it rather than the alloy itself. Machetes, kukris, swords and camp choppers mean long grinds, big surface areas and a lot of belt time — and a fair amount of 5160 arrives as reclaimed leaf spring with scale, pitting and a curve to grind out. None of it is hard. It is just more work than a six-inch hunter.

Grinding Annealed 5160

Annealed 5160 hogs quickly and predictably with 36 to 60 grit ceramics. If you are working new bar stock, it behaves exactly as you would expect. If you are working reclaimed leaf spring, budget extra belts and extra time: there is mill scale and often surface pitting to get through before you see clean steel, and you need to grind deep enough to be sure any fatigue cracking from the spring’s service life is gone. A cracked spring makes a cracked blade.

The Long-Blade Problem

The real skill on a 5160 machete or sword is consistency, not removal. Long bevels magnify every wobble, and a grind line that drifts a millimetre over three inches is invisible until it drifts ten over thirty. Work in full-length passes rather than sections, keep the platen flat, and check your grind line against the spine frequently rather than at the end. Long thin blades also flex under belt pressure, which quietly changes your grind angle — support the blade and ease off.

Grinding Hardened 5160

At 57 to 59 HRC, hardened 5160 is one of the more cooperative steels you can put on a belt — low carbide content and moderate hardness mean it cuts cleanly. Its 400 to 450°F temper also gives you slightly more thermal headroom than a hard-run steel like O1 or 15N20. That is not permission to grind hot: it just means an honest mistake is more likely to be recoverable. Keep it moving, dip regularly, and slow the machine for finishing.

Belt Progression

• Scale and spring cleanup: 36 grit ceramic, and expect to spend belts on reclaimed stock
• Hogging (annealed): 36–60 grit ceramic
• Bevel setting: 60–120 ceramic or zirconia — full-length passes on long blades
• Refinement: 220–400
• Finishing: Trizact, structured abrasives or hand sanding — though for a working chopper, many makers stop at a belt finish or go straight to a forced patina

Full belt-selection logic in the Belt Buyer’s Guide.

Sharpening 5160

5160 sharpens fast on anything, and that is a genuine feature rather than a consolation prize. It has no wear-resistant carbides, so a few passes on a stone, a puck or even a smooth file will bring a chopper back to working sharp in the field — which is exactly what a machete or camp knife needs. Do not chase a razor apex on a chopping blade: run 20–25° per side with a slightly convex edge, which is far more durable against impact than a crisp V-bevel. Kitchen and slicing work in 5160 is rare but can go finer. Method in How to Sharpen a Knife, and the reasoning behind edge angles in Why Hardness Matters.

Sources

• Knife Steel Nerds — Optimizing Toughness of Knife Steels
• Alpha Knife Supply — 5160 technical data