HeatTreat: Steel Calculator

HeatTreat computes the numbers you need to heat treat steel, and shows you where every one of them came from. Pick a grade or enter your own composition, and get critical temperatures, retained austenite, tempering equivalence and carbon equivalents, each with the equation that produced it, the paper it was published in, and a plain statement of where it stops being reliable. Built for knife makers and blacksmiths first, then heat treat shops, students and engineers. Every number shows its work The equation, written out The full citation: author, journal, year, pages A check against the range the correlation was actually fitted on A refusal when your chemistry sits outside what the correlation can honestly cover That last one is the point. Ac3 is withheld for hypereutectoid steels rather than guessed. Tool steel and stainless chemistry is refused by the low-alloy correlations rather than extrapolated into nonsense. A withheld number is honest. A silently wrong one is not. 32 steels, each with its basis stated Carbon, alloy, tool and martensitic stainless grades, searchable across AISI, EN/DIN, JIS and old British designations. Every record says whether its chemistry is a standard range or producer-typical values, and lists its sources. Included: 1018, 1045, 1060, 1075, 1080, 1084, 1095, 15N20, 26C3, 4130, 4140, 4340, 5160, 6150, 8620, 9260, 9310, 52100, 80CrV2, 300M, W1, O1, A2, D2, S7, H13, M2, 420, 440C, AEB-L, 154CM and CPM MagnaCut. Each grade page carries chemistry, cross-references with equivalence quality marks, typical published practice (austenitizing band drawn on the glow scale, quench medium, temper range, expected hardness), and a one-tap jump into the calculator. What it calculates Ac1 and Ac3, the lower and upper critical temperatures (Andrews 1965) Ms, martensite start, with Steven and Haynes 1956 and Payson and Savage 1944 shown next to Andrews as a visible spread, because three published fits disagree and pretending otherwise would be dishonest Bs, bainite start (Steven and Haynes 1956) Retained austenite after quenching (Koistinen and Marburger 1959), with room, freezer, dry ice and liquid nitrogen quench-finish presets Tempering equivalence (Hollomon and Jaffe 1945): two hours at 200 C is about eighteen minutes at 220 C, with the embrittlement-window caveat shown in the working CE(IIW), Pcm and CET carbon equivalents, with weldability context Reference, always to hand Forge glow colors, from black heat to white, with the honest caveat that eye-judged color shifts with ambient light Temper oxide colors Grossmann quench severity for common media Celsius or Fahrenheit throughout The eight papers every number in the app comes from, cited in full Private by design No account, no sign-up No ads, no tracking, no analytics, no data collection No internet permission at all. The app cannot make a network call, even by accident. Works on the shop floor, at the forge, or in a basement lab with no signal Please note: HeatTreat gives engineering estimates from published empirical correlations, not specifications. Correlations carry scatter, and your steel, your furnace and your quench are not the ones the equations were fitted on. Verify against the applicable standard, your supplier's data, and your own test coupons before committing work.

New in 1.1: - Hardness after quenching and after your temper, in HRC and HV - Hardenability: the largest bar that hardens through in brine, water or oil - Weld preheat and carburizing case depth - Equations now typeset, plus a glossary: tap (i) on any result - A new More tab with reference charts and guides