For replacement work on older equipment, 5/16-18 x 1 1/4 keeps the UNC pitch patch, length, and square-head drive clear in the product record.

Typical applications include farm implements, mill equipment, and production machinery that need wrench clearance. Point choice is part of the order detail, with Half Dog, Full Dog, Cone, Oval, and Flat handled under this family. Point selection should reflect the shaft feature, acceptable marking, and expected service adjustment.

Cold Headers keeps this legacy set screw family practical for maintenance, repair, and production users who still need the square-head form. Review the selected point, wrench clearance, and mating feature before substitution. Cup point slotted set screws are the related screwdriver-driven option when flush-fitting access is preferred.

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: 1 1/4 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)
• Head Radius (W): 0.78 in. (min)
• Neck Relief: (K) 0.240 / 0.225 in. dia. (max/min), (U) 0.111 in. min width, (S) 0.036 in. min fillet
• Dimensional Standard: ASME B18.6.2

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