Temper: Knife Heat Treat
Knife heat-treat schedules
Free · In‑App Purchases · Designed for iPad. Not verified for macOS.
Cited heat-treat schedules for 20 knife steels, per-use-case HRC targets, named failure-mode warnings — all linking back to Knife Steel Nerds.
Temper is a shop-floor reference for knife heat-treatment. Every schedule cites a primary source — a Knife Steel Nerds article by Larrin Thomas or the steel manufacturer's datasheet — with a direct link, so you can verify the page that the recipe comes from.
WHAT'S INSIDE
• 20 steel schedules — simple carbon (1084, 80CrV2, 1095, 8670, 15N20), spring/tool (52100, 5160, O1, A2, D2), stainless (AEB-L, 14C28N, CPM-154, S35VN, S45VN), and PM super-steels (M390, CPM-3V, CPM MagnaCut, MagnaMax, ApexUltra).
• Per-use-case HRC targets — Kitchen, EDC, Hunter, hard-use chopper. Each steel maps to a hardness range that works for the use the blade actually sees.
• Named failure-mode warnings — six surfaced inline when they apply: 5160 grain growth past 1525°F, undersoaking, quench-to-cryo delay, retained austenite from over-austenitizing, one second past nonmagnetic in simple carbons, and wrong quench medium for stainless. Each cites the specific Larrin Thomas article it came from.
• Quench-medium guidance — primary, acceptable alternates, and a hard interlock for blocked media (never water-quench plain carbon; never oil-quench stainless or PM).
• Cryo decision matrix — per-steel-class retained-austenite framing with named cryo media (household freezer, dry ice + acetone, liquid nitrogen).
• HRC ↔ HV ↔ HB ↔ tensile conversions — from ASTM E140-12b Table 1.
• Source-version stamps — every schedule shows when the cited source was last updated, so you know if your reference has shifted.
FREE TIER
Three starter steels — 1084, 80CrV2, AEB-L — are free permanently with full citations and warnings. You can heat-treat a 1084 blade end-to-end on the free tier. The IAP is for breadth, not depth.
UNLOCK ($6.99, ONE-TIME)
The Temper Unlock IAP adds:
• The other 17 steel schedules
• Per-steel saved profile — persist the schedule you actually used and the HRC you actually measured
• Multi-session log — every heat-treat run with date, austenitize, soak, quench, cryo, temper, measured HRC, and notes
No subscriptions. No ads. No account.
DISCLAIMER
Temper presents Knife Steel Nerds and steel-manufacturer guidance for educational purposes. Verify schedules against current Knife Steel Nerds articles and your steel supplier's spec sheet before heat-treating.
CITATIONS
Schedules reference Larrin Thomas's articles at knifesteelnerds.com and datasheets from New Jersey Steel Baron, Crucible Industries, and Bohler-Uddeholm. Hardness conversions are from ASTM E140-12b Table 1 (Non-Austenitic Steels).
Ratings & Reviews
The developer, Roman Kopaliani, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
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Information
- Seller
- Roman Kopaliani
- Size
- 721.9 KB
- Category
- Utilities
- Compatibility
Requires iOS 17.0 or later.
- iPhone
Requires iOS 17.0 or later. - iPad
Requires iPadOS 17.0 or later. - Mac
Requires macOS 14.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- In-App Purchases
Yes
- Temper Unlock (lifetime) $6.99
- Copyright
- © 2026 Roman Kopaliani