banner
img
img

ASTM A193 Grade B7M

ASTM A193 grade B7M includes chromium-molybdenum alloy steel fasteners covered in this basic material specification. These high-tensile fasteners are in high demand in chemical and petroleum construction applications. They are made by quenching and tempering in the heat to attempt the necessary hardness and mechanical properties. The bolting solutions are mainly implemented in extensive pressure and temperature-related services like fittings, pressure valves, flanges, and valves. The distinction between B7M and B7 is the testing necessary for hardness in every fastener.

A193 Grade B7M

B7M Alloy steel, AISI 4140/4142 quenched and tempered

Mechanical properties

Size Tensile ksi, min Yield ksi, min Elong %, min RA % min HBW Rockwell
Up to 4 100 80 18 50 235 Max -
Over 4 - 7 100 75 18 50

Chemical properties

Element B7 (AISI 4140)
Carbon 0.37 - 0.49%
Manganese 0.65 - 1.00%
Phosphorus, max 0.035%
Sulfur, max 0.040%
Silicon 0.15 - 0.35%
Chromium 0.80 - 1.10%
Nickel -
Molybdenum 0.15 - 0.25%

Compatible hardware

Bolt Grade Nut Washers
B7M A194 Grade 2HM F436