{"id":6257,"date":"2026-09-25T21:11:14","date_gmt":"2026-09-25T18:11:14","guid":{"rendered":"https:\/\/www.defencemetal.com\/index.php\/2026\/09\/25\/aisi-431-aisi-410-difference\/"},"modified":"2026-09-30T10:44:11","modified_gmt":"2026-09-30T07:44:11","slug":"aisi-431-aisi-410-difference","status":"publish","type":"post","link":"https:\/\/www.defencemetal.com\/index.php\/2026\/09\/25\/aisi-431-aisi-410-difference\/","title":{"rendered":"What Is the Difference Between AISI 431 and AISI 410?"},"content":{"rendered":"

AISI 431<\/strong> and AISI 410<\/strong> are both martensitic stainless steels and both harden on quenching. The difference is 431’s markedly higher chromium and its added nickel<\/strong> — which makes it the most corrosion-resistant member of the conventional martensitic family.<\/p>\n

The chromium and nickel difference<\/h3>\n

AISI 410’s chromium runs from 11.50 to 13.50 % and nickel is an impurity (0.75 % max). In AISI 431 chromium rises to 15.00–17.00 %<\/strong> and nickel enters the specification. The result is a martensitic steel that can stand up to marine atmospheres.<\/p>\n

Carpenter Technology, BGH Edelstahlwerke, Deutsche Edelstahlwerke and Universal Stainless — four separate organisations — describe 431 as the most corrosion-resistant of the hardenable 400-series grades and suitable for marine atmospheric service.<\/p>\n

Compared in figures<\/h3>\n
\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
PROPERTY<\/th>\nAISI 431 (1.4057)<\/th>\nAISI 410 (1.4006)<\/th>\n<\/tr>\n<\/thead>\n
Chromium (Cr)<\/strong><\/td>\n15.00 – 17.00 %<\/strong><\/td>\n11.50 – 13.50 %<\/strong><\/td>\n<\/tr>\n
Silicon (Si)<\/td>\n1.00 % max<\/td>\n1.00 % max<\/td>\n<\/tr>\n
Phosphorus (P)<\/td>\n0.040 % max<\/td>\n0.040 % max<\/td>\n<\/tr>\n
Sulphur (S)<\/td>\n0.030 % max<\/td>\n0.030 % max<\/td>\n<\/tr>\n
Nickel (Ni)<\/td>\nsee note below<\/td>\n0.75 % max<\/td>\n<\/tr>\n
Carbon (C)<\/td>\nsee note below<\/td>\n0.08 – 0.15 %<\/td>\n<\/tr>\n
Proof strength (Rp0.2), +QT800<\/td>\n\u2265 600 MPa<\/td>\n—<\/td>\n<\/tr>\n
Proof strength (Rp0.2), +QT900<\/td>\n\u2265 700 MPa<\/td>\n—<\/td>\n<\/tr>\n
Proof strength (Rp0.2), +QT650<\/td>\n—<\/td>\n\u2265 450 MPa<\/td>\n<\/tr>\n
Tensile strength (Rm), +QT650<\/td>\n—<\/td>\n650 – 850 MPa<\/td>\n<\/tr>\n
Annealed hardness<\/td>\n\u2264 295 HBW<\/td>\n—<\/td>\n<\/tr>\n
Hardening temperature<\/td>\n950 – 1060 \u00b0C, oil<\/td>\n950 – 1010 \u00b0C<\/td>\n<\/tr>\n
Sub-critical anneal<\/td>\n680 – 800 \u00b0C<\/td>\n—<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

Note on nickel:<\/em> ASTM A276 and Carpenter give 1.25–2.50 %; BGH, Deutsche Edelstahlwerke and Rodacciai give 1.50–2.50 %. Note on carbon:<\/em> ASTM A276, Carpenter and BGH give 0.20 % max with no minimum, while Deutsche Edelstahlwerke and Rodacciai give 0.12–0.22 % for EN 10088-3. We do not reduce these two rows to a single value — the sources genuinely diverge.<\/p>\n

What to watch when ordering — two serious traps<\/h3>\n
\n

An order for “431 to ASTM A276” carries no strength guarantee.<\/p>\n

ASTM A276 tabulates no tensile requirement<\/strong> for Type 431 in Condition T or H; it gives only a hardness limit for Condition A. An order reading “431 to A276” is therefore empty as far as strength is concerned. Specify the strength you need separately, or order to an aerospace specification.<\/p>\n<\/div>\n

\n

ASTM 431 and EN 1.4057 are not the same chemistry.<\/p>\n

ASTM sets no carbon minimum; EN sets one at 0.12 %. A bar at 0.05 % carbon may meet ASTM 431 but will not meet 1.4057.<\/strong> The nickel minimum also differs. If both specifications must be met, write carbon 0.12–0.20 % and nickel 1.50–2.50 % into the contract.<\/p>\n<\/div>\n

The tempering range to avoid<\/h3>\n

In both steels a particular tempering range reduces toughness and corrosion resistance. Carpenter points to 371–565 \u00b0C for 431 and 399–566 \u00b0C for 410. Deutsche Edelstahlwerke adds that 1.4057 is susceptible to 475 \u00b0C embrittlement<\/strong> and that 420–520 \u00b0C should be avoided.<\/p>\n

On welding the sources diverge: Carpenter requires 204–316 \u00b0C preheat and 649 \u00b0C post-weld heat treatment for 431, while Deutsche Edelstahlwerke rates 1.4057’s weldability as “good”. We do not issue a single verdict; if you are planning welded fabrication, agree the procedure with your material supplier.<\/p>\n

Where are they used?<\/h3>\n

AISI 431:<\/strong> aircraft fasteners and fittings, pump shafts, valve stems, piston rods, structural parts working in marine environments.<\/p>\n

AISI 410:<\/strong> turbine blades, valves, pumps, gate valves, fasteners, refinery internals, cutlery.<\/p>\n

In short: both offer strength; when the environment is corrosive you step up to 431.<\/strong><\/p>\n

Designations, standards and AMS equivalents<\/h3>\n

The same steel is called different things depending on which system you are speaking in. Most ordering and certification confusion starts here, so a short summary:<\/p>\n