5/16-18 x 3 1/2 gives maintenance teams a classic square-head set screw with a full UNC callout and a wrench-driven head for heavy mechanical layouts.

Typical applications include pulleys and sheaves on line shafts where the head is intentionally exposed. The row represents a square-head size, while the point selection is made from Half Dog, Full Dog, Cone, Oval, and Flat. Half Dog points register into shallow holes or slots when location matters under load.

Cold Headers keeps the record focused on usable engineering details so buyers can compare the callout against drawings and service notes. Review the selected point, wrench clearance, and mating feature before substitution. External wrench access is useful when an internal socket recess would be hard to keep clear.

Technical Highlights

• Head: Square, wrench-driven
• Material: Low Carbon Steel, Case Hardened
• Point Styles: Half Dog, Full Dog, Cone, Oval, Flat (specify at order)
• Thread Size: 5/16-18 (UNC)
• Thread Fit: 2A (per ASME B18.6.2)
• Length: 3 1/2 in.
• Width Across Flats (F): 0.312 / 0.302 in. (max/min)
• Across Corners (G): 0.442 / 0.415 in. (max/min)
• Head Height (H): 0.245 / 0.224 in. (max/min)
• Dimensional Standard: ASME B18.6.2

Call 773-775-7900 or email Sales@coldheaders.com for pricing, availability, or a quote.