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).
Maintenance update. No feature changes.
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