High-end forging steel (52100-style 1.5Cr base + W/V) by Larrin Thomas & co. Furnace: austenitize 1525–1625°F / 10–15 min, oil quench, temper 300–450°F — tested to 465°F with no embrittlement. Capable of 61–68+ HRC. Forging: normalize 1750°F, grain-refine 1450°F, forge ≤2050°F.
⚠︎ Composition is the published design basis (52100-type 1.5Cr-0.3Mn-0.3Si + ~2.5% W + V); temper↔HRC points are read from KSN tempering charts — verify with the ApexUltraSteel datasheet.
Temper → hardness chart
Approximate HRC after a double-temper at each temperature (from the sources below). Set your target and pick the matching temper.
Temper °F
Temper °C
Hardness
300°F
149°C
66 HRC
350°F
177°C
65 HRC
400°F
204°C
64 HRC
450°F
232°C
62.5 HRC
Composition (typical, wt%)
Element
%
C
1.25%
Cr
1.5%
V
0.25%
W
2.5%
Mn
0.3%
Si
0.3%
Design basis per KSN lab-development article
HeatTreatBench — the recipes in your shop, offline
Get the full ApexUltra recipe plus 25 more steels offline — set your target HRC and the app gives you the exact temper, with a forge timer and a per-blade log. Works in the shop with no signal.