Heat-treating CPM-S45VN with stainless tool wrap
Higher chromium and nitrogen — more corrosion resistance than S35VN.
Recommended SSTW grade
Grade 309 stainless foil
CPM-S45VN austenitizes around 2050°F — above ~2000°F — so 309 stainless foil holds up to the heat and longer soaks without embrittling.
Shop 309 tool wrap rollsCPM-S45VN heat-treat reference
- Austenitizing temp
- 1950–2050°F
- Soak at temp
- 15–30 min
- Quench
- Plate quench, then cryo
- Temper
- Per Crucible spec
- Typical uses
- Premium EDC, hard-use stainless
General knifemaking guidance — always follow the steel manufacturer's published data sheet for your exact stock.
Why wrap CPM-S45VN in stainless foil
At 2050°F the bare surface of CPM-S45VN oxidizes and loses carbon (decarburization), leaving a soft, scaled skin you have to grind back past. Sealing the blade in SSTW 309 stainless tool wrap keeps oxygen off the steel through the soak and quench, so it comes out of the kiln bright with full hardness right to the edge — less post-heat-treat grinding, no decarb surprises.
CPM-S45VN foil FAQ
Do I need stainless foil to heat treat CPM-S45VN?
Wrapping CPM-S45VN in stainless tool wrap before the kiln prevents surface scale and decarburization, so the blade comes out clean with the carbon at the edge intact. It is strongly recommended for CPM-S45VN, especially for air- and plate-quenched work where the blade sits at temperature.
Which SSTW grade should I use for CPM-S45VN — 309 or 321?
CPM-S45VN austenitizes around 2050°F — above ~2000°F — so 309 stainless foil holds up to the heat and longer soaks without embrittling.
What temperature is CPM-S45VN heat treated at?
CPM-S45VN is commonly austenitized around 1950–2050°F with a 15–30 min soak, then plate quench, then cryo and tempered (Per Crucible spec). Always confirm against the steel mill's published data sheet for your exact stock — these figures are general knifemaking guidance.
Can I use 321 foil for CPM-S45VN?
321 works for many sub-2000°F heat treats, but CPM-S45VN runs hot enough that 309 stainless foil is the safer choice — it tolerates the higher austenitizing temperature and longer soaks without embrittling.
Ready to heat treat CPM-S45VN clean?
SSTW Grade 309 stainless tool wrap, sold by the roll and shipped from the USA.
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