SSTW — Stainless Steel Tool Wrap — Master Your Craft

Heat-treating D2 with stainless tool wrap

High-chromium tool steel with great wear resistance and a semi-stainless edge.

Recommended SSTW grade

Grade 321 stainless foil

D2 austenitizes at or below ~2000°F, so 321 stainless foil is the right everyday choice — full scale and decarb protection at a lower cost per roll.

Shop 321 tool wrap rolls

D2 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 321 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 at or below ~2000°F, so 321 stainless foil is the right everyday choice — full scale and decarb protection at a lower cost per roll.

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.

Ready to heat treat D2 clean?

SSTW Grade 321 stainless tool wrap, sold by the roll and shipped from the USA.

Shop tool wrap rolls