{"id":3667,"date":"2026-09-16T11:16:20","date_gmt":"2026-09-16T08:16:20","guid":{"rendered":"https:\/\/www.defencemetal.com\/index.php\/en\/aisi-304l\/"},"modified":"2026-09-25T16:30:22","modified_gmt":"2026-09-25T13:30:22","slug":"aisi-304l","status":"publish","type":"page","link":"https:\/\/www.defencemetal.com\/index.php\/en\/aisi-304l\/","title":{"rendered":"AISI 304L \/ (1.4307)"},"content":{"rendered":"

<\/p>\n

AISI 304L \/ (1.4307) \/ UNS S30403 \/ AMS 5511 \/ AMS 5513<\/h1>\n
DEFENCE METAL<\/span><\/p>\n
\n
AISI 304L<\/div>\n
UNS S30403 \u00b7 W.Nr. 1.4307 \u00b7 X2CrNi18-9 \u00b7 17.5-20.0% Cr \u2013 8.0-12.0% Ni \u2013 C \u2264 0.030% (ASTM A240, A276, A479, A182, AMS 5647) or \u2264 0.035% (ASTM A312, A213; 0.040% allowed on thin wall) \u2013 balance Fe. It is an austenitic stainless steel: NOT PRECIPITATION HARDENABLE, it cannot be hardened by heat treatment; strength is raised only by cold work. Its ONLY difference from 304 is the carbon ceiling.<\/div>\n
\n
Not to be confused with<\/div>\n

AISI 304<\/a><\/div>\n<\/div>\n

\n
\n
For what<\/div>\n
Bought for welded fabrication: welded tanks, vessels, piping and frame parts where a post-weld solution anneal is not possible. Because the carbon ceiling is 0.030%, carbides do not in practice precipitate at the grain boundaries within the time of a welding thermal cycle;<\/div>\n<\/div>\n
\n
Forms<\/div>\n
Round bar \u00b7 flat bar \u00b7 plate \u00b7 sheet \u00b7 pipe and tube \u00b7 forging. All forms supplied to order.<\/div>\n<\/div>\n
\n
Standards<\/div>\n
AMS 5511<\/b> (sheet, strip, plate) \u00b7 AMS 5647<\/b> (bar, wire, forgings, mechanical tubing, rings, forging stock). ASTM: A240 \/ SA-240 (plate, sheet, strip) \u00b7 A276 \/ SA-276 and A479 \/ SA-479 (bar and shapes) \u00b7 A312 \/ SA-312 (pipe, TP304L) \u00b7 A213 \/ SA-213 and A249 (tube, TP304L) \u00b7 A182 \/ SA-182 (forged flanges and fittings, F304L) \u00b7 A403 (fittings, WP304L) \u00b7 A580 (wire) \u00b7 A484 (general requirements) \u00b7 A666. EN: 10088-2, 10088-3, 10028-7, 10216-5, 10217-7, 10222-5, 10272.
The AMS numbers are SEPARATE for 304 and 304L and must not be mixed. Those belonging to 304L are AMS 5511 (flat product) and AMS 5647 (bar, wire, forgings). AMS 5513 and AMS 5639 belong to 304, NOT to 304L.<\/span><\/div>\n<\/div>\n
\n
Advantage<\/div>\n
That it can be used as-welded. Its carbon ceiling is 2.3 times lower than that of 304 (0.030% against 0.07%), and this directly limits how much carbon can precipitate in the sensitization band; a post-weld solution anneal is not normally required.<\/div>\n<\/div>\n
\n
Welding<\/div>\n
Filler metal: AWS E308L \/ ER308L (a low-carbon filler, which must match the carbon ceiling of the base metal); E308 \/ ER308 and 347 are also used. NO PREHEAT IS REQUIRED \u2014 the austenitic structure shows no transformation hardening. ASME Section IX P-No 8 (austenitic stainless).<\/div>\n<\/div>\n
\n
Limits<\/div>\n
CHLORIDE STRESS CORROSION CRACKING: under tensile stress in a chloride-bearing environment it cracks above roughly 60 \u00b0C. Atlas Steels, thyssenkrupp, Aalco, Alleima and the buymetal grade sheet give this threshold as about 60 \u00b0C; Outokumpu says about 50 \u00b0C and ATI about 49 \u00b0C (120 \u00b0F) \u2014 NO SINGLE NUMBER IS GIVEN;<\/div>\n<\/div>\n
REQUEST A QUOTE<\/a>All stainless steels →<\/a>TECHNICAL DETAILS ↓<\/span><\/div>\n
Compiled from manufacturer data sheets \u00b7 confirm against the current specification before ordering<\/div>\n<\/div>\n<\/div>\n

<\/p>\n