CPM-3V heat treat: austenitize, quench & temper chart
CPM-3V is a powder metallurgy 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 CPM-3V heat-treat schedule
Austenitize: 1850–2150°F (1950°F recommended), hold 30 min once to temperature. A controlled oven or kiln beats forge colour for hitting this window repeatably.
Quench: Plate quench. Never use Water, Brine, Parks 50, Duratherm 48, Parks AAA, Canola oil. Plate quench. Soak time varies by austenitize temp: 45 min @ 1850°F → 10 min @ 2150°F.
Cryo (recommended): LN₂ 30–60 min — required for retained-austenite control at higher austenitize temps. Straight from the quench into cryo, then temper.
Temper: 2 passes of 2 h at 400°F for the recommended edge (~60–61 HRC). Temper twice for 2 hours. Larrin's testing favors low-temp tempering (300–500°F); the datasheet recommends 1000–1050°F (secondary hardening) — that's for tooling, not knives.
CPM-3V 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 |
|---|---|
| 300°F (149°C) | 61–62 HRC |
| 400°F (204°C) | 60–61 HRC |
| 500°F (260°C) | 59–60 HRC |
Target hardness for CPM-3V by knife type
| Use | Recommended HRC |
|---|---|
| Kitchen | 60–61 HRC |
| EDC | 60–61 HRC |
| Hunter | 59–60 HRC |
| Hard-use chopper | 58–59 HRC |
Most common mistake
Datasheet 1000–1050°F tempering is for tooling — not for knives. Use 300–500°F for blade applications.
FAQ
What temperature do you austenitize CPM-3V?
1850–2150°F, with 1950°F recommended, held 30 min once the steel is fully up to temperature.
What is the best quench for CPM-3V?
Plate quench. Never Water, Brine, Parks 50, Duratherm 48, Parks AAA, Canola oil. Plate quench. Soak time varies by austenitize temp: 45 min @ 1850°F → 10 min @ 2150°F.
What HRC does CPM-3V reach?
58–62 HRC across the usable tempering range; about 60–61 HRC for a kitchen knife. Temper at 400°F for ~60–61 HRC.
How do you temper CPM-3V?
2 passes of 2 h at 400°F for the recommended edge. See the chart above to pick a different tempering temperature for a harder or tougher blade.
Can you forge CPM-3V?
CPM-3V is best heat-treated in a controlled oven or kiln rather than forged by colour — its austenitizing window and quench are too tight to hit reliably by eye.
What you need to heat-treat CPM-3V
Repeatable hardness comes from controlling temperature and quench speed — eyeballing colour is how blades end up soft or cracked.
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- A heat-treat oven or kiln holds the 1950°F austenitizing temperature — the single biggest factor in repeatable hardness.
- Air-hardening steel plate-quenches between aluminium quench plates — no oil bath needed.
- Verify the result with a Rockwell hardness tester or hardness files — don't trust the schedule blind.
- Wrap in stainless tool-wrap foil to stop decarb and scale at high austenitizing temperatures.
Sources
Heat-treat schedules are the cited published values for CPM-3V; 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.