{"id":6250,"date":"2026-09-25T21:11:05","date_gmt":"2026-09-25T18:11:05","guid":{"rendered":"https:\/\/www.defencemetal.com\/index.php\/2026\/09\/25\/aisi-310-aisi-314-difference\/"},"modified":"2026-09-30T10:42:14","modified_gmt":"2026-09-30T07:42:14","slug":"aisi-310-aisi-314-difference","status":"publish","type":"post","link":"https:\/\/www.defencemetal.com\/index.php\/2026\/09\/25\/aisi-310-aisi-314-difference\/","title":{"rendered":"What Is the Difference Between AISI 310 and AISI 314?"},"content":{"rendered":"

AISI 310 (310S)<\/strong> and AISI 314<\/strong> are two austenitic stainless steels made for high-temperature service. Their chromium and nickel contents are identical. The difference between them lies in a single element: silicon<\/strong>.<\/p>\n

Why add silicon?<\/h3>\n

What protects a steel at high temperature is the chromium oxide layer that forms on its surface. As the temperature rises, that layer eventually becomes inadequate and scaling begins. The 1.50 to 2.50 % silicon<\/strong> added to AISI 314 makes the oxide layer more resistant and pushes the scaling temperature upward.<\/p>\n

The gain is concrete: to EN 10095 the continuous service temperature in dry air is 1050 \u00b0C for 310S and 1150 \u00b0C for 314<\/strong>. That roughly 100 \u00b0C difference is what the silicon buys.<\/p>\n

The price: embrittlement<\/h3>\n

Silicon is not free. Outokumpu states that 1.4841 (314) has a high susceptibility to embrittlement during continuous operation in the 600–950 \u00b0C range<\/strong>. The German stainless steel information centre (ISER) writes that 1.4841 is more susceptible than 1.4845 (310S), and that 1.4845 itself can embrittle in the 600–900 \u00b0C band.<\/p>\n

The practical consequence: if the temperature is steady and high, use 314; if there is heating and cooling cycling, use 310S.<\/strong> ISER notes that 310S is preferred under cyclic conditions because it forms a more adherent oxide scale.<\/p>\n

Compared in figures<\/h3>\n
\n\n\n\n\n\n\n\n\n\n\n\n\n
PROPERTY<\/th>\nAISI 310S (1.4845)<\/th>\nAISI 314 (1.4841)<\/th>\n<\/tr>\n<\/thead>\n
Carbon (C)<\/td>\nsee the warning below<\/td>\n0.20 % max<\/td>\n<\/tr>\n
Silicon (Si)<\/strong><\/td>\n1.50 % max<\/strong><\/td>\n1.50 – 2.50 %<\/strong><\/td>\n<\/tr>\n
Manganese (Mn)<\/td>\n2.00 % max<\/td>\n2.00 % max<\/td>\n<\/tr>\n
Sulphur (S)<\/td>\n—<\/td>\n0.015 % max<\/td>\n<\/tr>\n
Chromium (Cr)<\/td>\n24.00 – 26.00 %<\/td>\n24.00 – 26.00 %<\/td>\n<\/tr>\n
Nickel (Ni)<\/td>\n19.00 – 22.00 %<\/td>\n19.00 – 22.00 %<\/td>\n<\/tr>\n
Continuous service (EN 10095, dry air)<\/td>\n1050 \u00b0C<\/td>\n1150 \u00b0C<\/td>\n<\/tr>\n
Suitability for cyclic heating<\/td>\nbetter<\/td>\nless suitable<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

What to watch when ordering<\/h3>\n
\n

310, 310S and 1.4845 are three different carbon ceilings.<\/p>\n

ASTM Type 310 (S31000) allows carbon up to 0.25 %; ASTM 310S (S31008) up to 0.08 %; EN 1.4845 up to 0.10 %. So a bar certified to 1.4845 at 0.09 % carbon does not meet ASTM 310S.<\/strong> State clearly which one you want.<\/p>\n

Likewise 1.4841 and UNS S31400 are not identical: EN 1.4841 limits silicon to 1.50–2.50 % while ASTM S31400 permits 1.50–3.00 %. A heat at 2.8 % silicon meets S31400 but fails 1.4841.<\/p>\n<\/div>\n

Two warnings<\/h3>\n

The intermittent temperature can be lower than the continuous one.<\/strong> In these two grades the scale spalls under thermal cycling, so the intermittent service limit is sometimes below the continuous one. Any source quoting a single “maximum temperature” without saying whether it is continuous or cyclic is therefore unusable.<\/p>\n

Neither is a wet-corrosion steel.<\/strong> High nickel does not make these grades suitable for aqueous service; both are susceptible to intergranular corrosion. In carburising atmospheres, 310 and 314 should be replaced by nickel-base alloys.<\/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