316 vs 316L: high-temperature strength vs weld corrosion resistance
316 has higher carbon and better high-temperature strength; 316L is low-carbon with better post-weld corrosion resistance. Select by standard and service condition — do not swap blindly.
316 and 316L both contain molybdenum (about 2%–3% Mo). The difference mirrors 304/304L:
• 316: C 0.04%–0.10% depending on standard; better high-temperature strength and creep performance, often used for elevated-temperature pressure parts.
• 316L: C ≤0.03%; better intergranular corrosion resistance after welding; the common choice for chemical, food and medical equipment.
Selection points:
1) High-temperature (>450°C) pressure service where the design code requires 316: do not substitute 316L directly.
2) Welded structures at ambient corrosion conditions: 316L is the safer choice.
3) For dual-certified purchases, verify the carbon range and guaranteed mechanical values.
4) 316H (higher carbon) serves even higher temperatures; assess per code.
In short: 316 and 316L are not a simple upgrade path — they are two routes for different temperatures and welding conditions.
