A320 L7M Stud Bolts
Controlled-hardness L7 for cold sour service — 22 HRC max, NACE MR0175 compliant, Charpy tested at −100 °F.
Threaded rod inserted through the holes of mating flanges, paired with heavy hex nuts. Available in every diameter and length, imperial and metric, for flanged connections in critical service. Supplied bare or coated, with full material traceability.
ASTM A320 Grade L7M combines the low-temperature toughness of A320 with the hardness limit sour service demands. It is the same Cr-Mo steel as L7, tempered to a maximum of 235 HBW, tensile strength 100 ksi minimum, and Charpy tested at −100 °F. Like B7M, every piece is hardness tested.
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What A320 L7M must meet.
| Nominal diameter (in.) | Tensile strength, min (ksi) | Yield strength 0.2% offset, min (ksi) | Elongation in 2 in., min (%) | Reduction of area, min (%) | Hardness, max |
|---|---|---|---|---|---|
| 2½ and under | 100 | 80 | 18 | 50 | 235 HBW / 99 HRB (200 HBW / 93 HRB min) |
Values per ASTM A320/A320M-26, Tables 1, 2 and 3 (verified against the specification). Confirm the edition called out on your purchase order with our estimating team. L7M: 235 HBW / 99 HRB max and 200 HBW / 93 HRB min, tested on every piece.
Quenched in liquid and tempered at 1150 °F (621 °C) minimum, after all machining and threading. Hardness verified on every piece; Charpy impact tested per lot.
Full A320 L7M data sheet: chemistry, physical properties and standards →
Made to standard or to your drawing.
- Cold-climate sour gas wellheads
- Sour gas processing and sweetening plants
- Arctic and offshore H₂S service
- Low-temperature amine units
- Any A320 L7 application with NACE compliance