5160 heat treat: austenitize, quench & temper chart
5160 is a spring / tool knife steel. Here is the full heat-treat schedule — austenitizing temperature, quench, cryo and a tempering-temperature chart mapping each temper to final HRC — with every number cited to the source, not guessed.
The 5160 heat-treat schedule
Austenitize: 1500–1525°F (1525°F recommended), hold 15 min once to temperature. A controlled oven or kiln beats forge colour for hitting this window repeatably.
Quench: Parks 50. Also acceptable: Duratherm 48, Parks AAA, Canola oil. Never use Water, Brine. Parks 50 with 15 min LN₂ is Larrin's tested protocol. Canola works for forge mode.
Cryo (recommended): 15 min LN₂ included in Larrin's optimal protocol. Skipping cryo may improve toughness slightly with a hardness drop. Straight from the quench into cryo, then temper.
Temper: 2 passes of 1 h at 375°F for the recommended edge (~59–60 HRC). Temper twice for 1 hour. 5160 is sensitive to temper temperature — 375°F is the toughness sweet spot.
5160 tempering-temperature chart
Two-hour temper (×2), HRC after cryo where used. Pick the tempering temperature for the hardness your knife needs:
| Tempering temperature | Resulting hardness |
|---|---|
| 350°F (177°C) | 60 HRC |
| 375°F (191°C) | 59–60 HRC |
| 400°F (204°C) | 58–59 HRC |
| 450°F (232°C) | 57–58 HRC |
Target hardness for 5160 by knife type
| Use | Recommended HRC |
|---|---|
| Kitchen | 59–60 HRC |
| EDC | 59–60 HRC |
| Hunter | 58–59 HRC |
| Hard-use chopper | 58–59 HRC |
Forging 5160
Forge-friendly. Larrin's testing confirms forge schedules; leaf-spring stock is widely available.
Most common mistake
Temper sensitivity — 350°F gives less than half the toughness of 375°F. Above 1550°F austenitize, toughness drops sharply from grain growth.
FAQ
What temperature do you austenitize 5160?
1500–1525°F, with 1525°F recommended, held 15 min once the steel is fully up to temperature.
What is the best quench for 5160?
Parks 50. Duratherm 48, Parks AAA, Canola oil also work. Never Water, Brine. Parks 50 with 15 min LN₂ is Larrin's tested protocol. Canola works for forge mode.
What HRC does 5160 reach?
57–60 HRC across the usable tempering range; about 59–60 HRC for a kitchen knife. Temper at 375°F for ~59–60 HRC.
How do you temper 5160?
2 passes of 1 h at 375°F for the recommended edge. See the chart above to pick a different tempering temperature for a harder or tougher blade.
Can you forge 5160?
Forge-friendly. Larrin's testing confirms forge schedules; leaf-spring stock is widely available.
What you need to heat-treat 5160
Repeatable hardness comes from controlling temperature and quench speed — eyeballing colour is how blades end up soft or cracked.
- A heat-treat oven or kiln holds the 1525°F austenitizing temperature — the single biggest factor in repeatable hardness.
- Quench in Parks 50 for the cited as-quenched hardness.
- Verify the result with a Rockwell hardness tester or hardness files — don't trust the schedule blind.
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Sources
Heat-treat schedules are the cited published values for 5160; every furnace, quench and blade geometry varies, so verify against your own hardness testing. Getting steel to non-magnetic is not the same as reaching austenitizing temperature — use a controlled oven or kiln for repeatable results.