Heat-treating Sandvik 12C27 with stainless tool wrap
Clean Scandinavian stainless with great toughness and easy sharpening.
Recommended SSTW grade
Grade 309 stainless foil
Sandvik 12C27 austenitizes around 1975°F — above ~1800°F — so 309 stainless foil holds up to the heat and longer soaks without embrittling.
Shop 309 tool wrap rollsSandvik 12C27 heat-treat reference
- Austenitizing temp
- 1900–1975°F
- Soak at temp
- 10–15 min
- Quench
- Plate quench
- Temper
- 300–400°F, 2× 2 hr
- Typical uses
- Kitchen, outdoor, EDC
General knifemaking guidance — always follow the steel manufacturer's published data sheet for your exact stock.
Why wrap Sandvik 12C27 in stainless foil
At 1975°F the bare surface of Sandvik 12C27 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.
Sandvik 12C27 foil FAQ
Do I need stainless foil to heat treat Sandvik 12C27?
Wrapping Sandvik 12C27 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 Sandvik 12C27, especially for air- and plate-quenched work where the blade sits at temperature.
Which SSTW grade should I use for Sandvik 12C27 — 309 or 321?
Sandvik 12C27 austenitizes around 1975°F — above ~1800°F — so 309 stainless foil holds up to the heat and longer soaks without embrittling.
What temperature is Sandvik 12C27 heat treated at?
Sandvik 12C27 is commonly austenitized around 1900–1975°F with a 10–15 min soak, then plate quench and tempered (300–400°F, 2× 2 hr). 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 Sandvik 12C27?
321 works for many sub-1800°F heat treats, but Sandvik 12C27 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 Sandvik 12C27 clean?
SSTW Grade 309 stainless tool wrap, sold by the roll and shipped from the USA.
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