What Is ASTM A182 F304L?
F304L is the low-carbon version of the F304 austenitic stainless forging (18Cr-8Ni, restricted carbon). The lower carbon level reduces chromium carbide precipitation in the heat-affected zone after welding, so welded components keep their corrosion resistance.
Temperature Range
Rated up to 538°C in the ASME B16.5 tables. Because of its lower room-temperature strength, F304L uses the lower Group 2.3 pressure-temperature rating curve — check the class before substituting for F304.
Material Group (per ASME B16.5)
Per ASME B16.5-2025 Table 1A, F304L belongs to Material Group 2.3, together with F316L and F317L low-carbon grades.
Corrosion Resistance
Same general corrosion behavior as F304 (Schweitzer tables, Type 304/347 row): excellent to good in most neutral and organic media, not recommended in hydrochloric and concentrated halide media. Its advantage is post-weld intergranular corrosion resistance — the reason to specify F304L for welded flanges and fittings.
Typical Applications
- Welded ASME B16.5 stainless flanges
- Welded B16.11 fittings and butt-weld components
- Storage tanks, vessels and piping where post-weld annealing is not practical
Chemistry & Mechanical Properties
Carbon limit and mechanical properties per ASTM A182 — consult the standard for exact limits. EN 10204 3.1 mill certificates supplied.
Related Standards
- ASME B16.5 — Pipe Flanges (NPS 1/2–24)
- ASME B16.11 — Socket-Welding & Threaded Fittings
- ASTM A182 F304 — Standard 304 Forgings
- ASTM A182 F316L — Low-Carbon 316
- Our Flange Range
FAQ
Why choose F304L over F304?
For welded construction: low carbon avoids sensitization (chromium carbide precipitation) in the weld heat-affected zone, preserving corrosion resistance without post-weld annealing.
Is F304L weaker than F304?
Yes — in B16.5 it carries the lower Group 2.3 rating, so at a given class and temperature the allowable pressure is below F304 (Group 2.1).
What temperature range does F304L cover?
Up to 538°C per the ASME B16.5 Group 2.3 tables.
Is F304L food-safe?
Yes, like 304 it is widely used in food and pharmaceutical equipment.
Can I substitute F304L for F304?
Yes, but note F304L carries the lower Group 2.3 pressure rating — check the allowable pressure at your design temperature before substituting.
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