Most blade work targets a finished hardness of 38 to 43 HRC. 410 stainless lands in that window naturally. 420 does not, and forcing it there causes problems.

420 carries more carbon and quenches much harder. To draw it down to roughly 41 HRC you have to temper between 425°C and 550°C (800°F to 1020°F), which sits in the middle of 420’s temper embrittlement range. That creates two manufacturing risks:

• Inconsistency. The hardness curve falls steeply through that window. A swing of only ±5°C in furnace temperature, or a drift in soak time, moves the final Rockwell enough to make statistical process control very difficult.
• Temper embrittlement. Holding in that range precipitates coarse chromium carbides (Cr₂₃C₆) at the grain boundaries. That cuts impact toughness and reduces corrosion resistance.

Tempering 420 above 600°C (1110°F) restores toughness, but the hardness overshoots downward and usually lands near 35 to 38 HRC.

410 has lower carbon and a lower peak as-quenched hardness, so it settles consistently in the 35 to 45 HRC range on safe, predictable tempering cycles. That is why we build from it.

If you need a tight 38 to 42 HRC with maximum corrosion resistance, a precipitation-hardening alloy such as 17-4 PH, aged on an H1025 or H1075 cycle, will hit that window with no embrittlement risk. Call us and we will talk it through.

Send a print or drawing with dimensions, material, quantity, and any tolerances. We will confirm any missing details.

Average turnaround is 2 to 3 days. Same-day service is available upon request.

Yes. We resharpen all types of blades and include straighten, balance, and demagnetize services at no extra charge.

Yes. We produce OEM-quality replacement blades built to spec.

Send what you have. We can often match a blade from an existing part or sample.

Call (319) 478-2718 or email jyoungblood@rangerblade.com with your print and quantity for a fast quote.

1561 S Main Street, Traer, IA 50675.

We serve processing, packaging, paper, textile, plastics, agriculture, and more.