1/2"-13 UNC-3A x 1.25" Low Head Socket Cap Screws
ASTM A453 Grade 660 Class B. Machined to the customer's drawing in our Houston shop.
Low Head Socket Cap Screws manufactured for high-temperature performance and precision fit 1/2"-13 UNC-3A x 1.25". ASME B18.3 ASTM A453 Grade 660 Class B (A-286 Stainless) Built for strength, heat resistance, and tight-tolerance applications.
Special socket products are machined from bar where the specification allows, with the socket broached and the threads rolled, or cut where the specification or order allows, then heat treated and plated as the specification requires. Shoulder, low-head, flat-head and set-screw patterns follow ASME B18.3 unless the drawing says otherwise.
About the material: A-286 bolting for the hottest joints — 130 ksi at room temperature and rated by stress-rupture at 1200 °F, for gas and steam turbines, exhaust and high-temperature process equipment. Read the A453 660 data page →
