Heat-treating D2 with stainless tool wrap
High-chromium tool steel with great wear resistance and a semi-stainless edge.
Recommended SSTW grade
Grade 309 stainless foil
D2 austenitizes around 1875°F — above ~1800°F — so 309 stainless foil holds up to the heat and longer soaks without embrittling.
Shop 309 tool wrap rollsD2 heat-treat reference
- Austenitizing temp
- 1800–1875°F
- Soak at temp
- 20–30 min
- Quench
- Air / plate
- Temper
- 400–1000°F per spec
- Typical uses
- Hunting, EDC, semi-stainless work knives
- Also known as
- 1.2379
General knifemaking guidance — always follow the steel manufacturer's published data sheet for your exact stock.
Why wrap D2 in stainless foil
At 1875°F the bare surface of D2 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.
D2 foil FAQ
Do I need stainless foil to heat treat D2?
Wrapping D2 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 D2, especially for air- and plate-quenched work where the blade sits at temperature.
Which SSTW grade should I use for D2 — 309 or 321?
D2 austenitizes around 1875°F — above ~1800°F — so 309 stainless foil holds up to the heat and longer soaks without embrittling.
What temperature is D2 heat treated at?
D2 is commonly austenitized around 1800–1875°F with a 20–30 min soak, then air / plate and tempered (400–1000°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 D2?
321 works for many sub-1800°F heat treats, but D2 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 D2 clean?
SSTW Grade 309 stainless tool wrap, sold by the roll and shipped from the USA.
Shop tool wrap rolls