Heat-treating CPM MagnaCut with stainless tool wrap
Modern balanced powder stainless — edge, toughness, and corrosion all at once.
Recommended SSTW grade
Grade 309 stainless foil
CPM MagnaCut austenitizes around 2150°F — above ~2000°F — so 309 stainless foil holds up to the heat and longer soaks without embrittling.
Shop 309 tool wrap rollsCPM MagnaCut heat-treat reference
- Austenitizing temp
- 2000–2150°F
- Soak at temp
- Per Niagara/Crucible spec
- Quench
- Plate quench, then cryo
- Temper
- 300–400°F per spec
- Typical uses
- Premium all-round knives
General knifemaking guidance — always follow the steel manufacturer's published data sheet for your exact stock.
Why wrap CPM MagnaCut in stainless foil
At 2150°F the bare surface of CPM MagnaCut 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 MagnaCut foil FAQ
Do I need stainless foil to heat treat CPM MagnaCut?
Wrapping CPM MagnaCut 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 MagnaCut, especially for air- and plate-quenched work where the blade sits at temperature.
Which SSTW grade should I use for CPM MagnaCut — 309 or 321?
CPM MagnaCut austenitizes around 2150°F — above ~2000°F — so 309 stainless foil holds up to the heat and longer soaks without embrittling.
What temperature is CPM MagnaCut heat treated at?
CPM MagnaCut is commonly austenitized around 2000–2150°F with a Per Niagara/Crucible spec soak, then plate quench, then cryo and tempered (300–400°F per 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 MagnaCut?
321 works for many sub-2000°F heat treats, but CPM MagnaCut 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 MagnaCut clean?
SSTW Grade 309 stainless tool wrap, sold by the roll and shipped from the USA.
Shop tool wrap rolls