Technical Threads supplies ASTM A193 B7 Socket Head Cap Screws for a variety of heavy industrial application. While not extremely common, B7 sockets are
widely considered to be the second most popular head style behind heavy/finished hex cap screws in B7.
The vast majority of alloy socket head cap screws are made to the much more common ASTM A574 specification. B7 sockets fill a very specific niche in the fastener application world.
Most sockets are used in high-strength applications. B7 sockets, on the other hand, are used for two specific purposes:
1) High temperature socket applications
2) Applications requiring higher ducility than A574’s
Both A574 sockets and B7 sockets are initially manufactured in a similar fashion. The initial heat treat until austenizations, and quenched/tempering process takes place for both. The difference is in the tempering temperature. B7 parts are tempered at 1150F; A574 are tempered at 650 F. The lower temp on the B7 means a softer part (increased ducility– less chance of snapping/breaking, impact on fatigue over lifespan, etc). In addition, the B7 is able to be used at approx a realistic 700-800F application temperature, while A574 sockets practically aren’t widely used for anything above 400-500F.
Consequently, B7 socket heads have found a home in temperature applications, especially in power, offshore and petro applications. Common equipment they are used on includes cylinders, turbines, feed pumps, condensors, heaters and more.
We supply ASTM A193 B7 socket head cap screws made to order. Quick shipping is available. Both UN8 and UNC threading is common, along with the rarer UNF.
Please contact us today! For more information on high temp sockets, see our B16 socket head cap screw information. Additionally, if you have a countersunk applications and prefer not to use an allen wrench, we offer B7 12 points (ferry bolts) and B16 12 points (ferry bolts).
Give us a call at 317-215-4781 or email us today!