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B7 / L7 / B7M / L7M

ASTM A193 B7 / B7M  and ASTM A320 L7 / L7M are standard chromium-molybdenum alloys steels used globally in the Oil & Gas and Petro-chemical industries. With near-identical chemical properties, B7 and L7 differ in their testing requirements - ASTM A320 L7 bolting is specified for low-temperature service, and as such has additional impact-testing requirements. The "M" suffix designates a lower maximum hardness and tensile strength. This may be beneficial when bolting is specified for sour gas service to mitigate the risk of embrittlement.

B7 / B7M / L7 / L7M

At Bolt King, we are adept at manufacturing B7 / B7M / L7 / L7M bolting on-site, manufacturing bolts, studbolts, Socket Head Cap Screws, and any other special requirement.  Our current range for hot-forging these products is M6 - M48.

If you have any questions or queries with regard to ASTM specification petro-chemical bolting, please contact us.

Chemical Properties - A193 B7/B7M



0.37 0.65 - - 0.15 0.75 - 0.15 - - - -
Max 0.49 1.10 0.035 0.040 0.35 1.20 - 0.25 - - - Bal

Mechanical Properties - A193 B7

Ultimate Tensile Strength (Min)Yield Strength  (Min)Elongation  (Min)RoA (Min)Hardness
860 MPa 720 MPa 16 50 35 HRC Max

Mechanical Properties - A193 B7M

Ultimate Tensile Strength (Min)Yield Strength  (Min)Elongation  (Min)RoA (Min)Hardness
690 MPa 550 MPa 18 50 22 HRC Max

The information provided above is for reference only. Please contact us for further information.

Special Fasteners In Exotic Alloys, Including
Inconel & Super Duplex