5160
5160 is the steel that made a thousand swords, machetes and camp choppers, and it earns that job honestly: a chromium-alloyed spring steel with only about 0.60% carbon, built to bend and come back rather than to hold a razor edge forever. The interesting thing about 5160 is that the makers who love it deliberately run it soft — 57–59 HRC — because pushing it to 60+ throws away the exact property they chose it for. If your blade is long, thick, or going to hit things, 5160 belongs on the shortlist.
5160 FAQ
What is 5160 steel good for?
Big blades that take abuse: swords, machetes, kukris, camp choppers, large bowies, hard-use field knives and tomahawks. Its toughness at working hardness is legendary and its price is low. It is a poor choice for a thin kitchen slicer — at 0.60% carbon it simply cannot match O1 or 52100 for edge retention.
What hardness should 5160 be heat treated to?
57–59 HRC. This is the single most important thing to know about the steel. Larrin Thomas’s toughness testing shows that 5160’s advantage is concentrated at moderate hardness — take it to 60–61 HRC and you have given up most of the toughness that justified choosing it, in exchange for edge retention that better steels would have given you anyway. Temper at 400–450°F and stop there.
How do you heat treat 5160?
Normalize and thermal cycle first, especially if forged — see Normalizing and Thermal Cycling. Austenitize at about 1525°F with a 10 minute soak, quench in a medium-fast oil, and temper twice at 400–450°F. The chromium gives it enough hardenability that it does not need a violent quench, which is part of why long blades survive the process.
Can you make a knife from a leaf spring?
Often yes — many vehicle leaf springs really are 5160 or something close to it. But “close to it” is the catch: you cannot confirm the alloy, the spring may be fatigue-cracked from service, and used springs need careful normalizing before they behave. Test-piece it before you commit hours to it. Full guidance in Making Knives from Files, Leaf Springs and Found Steel.
Is 5160 stainless?
No. The ~0.8% chromium is there for hardenability, not corrosion resistance. 5160 rusts like any carbon steel — oil it, dry it, and a forced patina suits its rough-and-ready character well.
5160 or 1084?
5160 for anything long or heavy, 1084 for smaller blades and first projects. 1084 is simpler to heat treat and takes a slightly harder edge; 5160 is dramatically more forgiving of impact and lateral load. See the 5160 vs 1084 comparison.
Also known as: AISI 5160, SAE 5160, ~DIN 1.7176 / 60CrMn4, commonly called leaf spring steel
Composition
Carbon 0.56–0.64%, Chromium 0.70–0.90%, Manganese 0.75–1.00%, Silicon 0.15–0.35%
Properties
| Property | Rating | Notes |
|---|---|---|
| Toughness | ★★★★★ | The whole reason to choose it. Low carbon content means very little excess carbide, and the chromium and manganese give clean, deep hardening — the result is a steel that bends, absorbs impact and returns rather than chipping or snapping. This is why it dominates sword and chopper work. Critically, the advantage lives at 57–59 HRC and is largely spent by 61 HRC. |
| Edge Retention | ★★☆☆☆ | Modest, and honestly so. At roughly 0.60% carbon there is neither the hardness nor the carbide volume for long slicing life — it will need touching up sooner than 1084, O1 or 52100. In exchange it sharpens back to working sharp in a few passes on almost any stone, which is the right tradeoff for a field blade. |
| Corrosion Resistance | ★☆☆☆☆ | None to speak of. The ~0.8% chromium is a hardenability alloy, not a stainless one. Expect rust on neglected blades and a fast patina on working ones — for a machete or camp knife that patina is a perfectly good protective finish. |
| Machinability / Grinding | ★★★★☆ | Grinds and files easily in the annealed state and forges beautifully, which is why it is a bladesmithing staple. Hardened 5160 at 57–59 HRC is also comparatively cooperative on the belt. New bar stock behaves far better than reclaimed leaf springs, which arrive with scale, service fatigue and unknown history. |
Heat Treatment
Normalize and thermal cycle first, especially for forged blades or reclaimed spring stock. Austenitize at ~1525°F with a 10 minute soak, quench in a medium-fast oil — the chromium provides enough hardenability that a violent quench is unnecessary, which helps long blades survive straight. Temper twice for two hours at 400–450°F to land 57–59 HRC. Resist going higher: above about 60 HRC you trade away the toughness that is 5160’s entire reason for existing.
Best Uses
Swords, machetes, kukris, camp choppers, large bowies, tomahawks and hard-use field knives — long or heavy blades that must survive impact and lateral load. Also a forgiving, inexpensive forging steel for learning to move metal.
Sources: Knife Steel Nerds — Optimizing Toughness of Knife Steels and 5160 property data (knifesteelnerds.com); AISI/SAE 5160 alloy specification