For line-shaft hardware, collars, and similar mechanical locations, 1/4-20 x 3 1/4 gives buyers the square-head set screw style named on many older drawings.

Typical applications include older machine tools that were designed around wrench-driven set screws. 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 supports square-head set screw sourcing with a catalog organized around exact size, standard, and point selection. Review the selected point, wrench clearance, and mating feature before substitution. For cup point square heads, use the separate Cup Point Square Head Set Screws category rather than this five-point family.

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: 1/4-20 (UNC)
• Thread Fit: 2A (per ASME B18.6.2)
• Length: 3 1/4 in.
• Width Across Flats (F): 0.250 / 0.241 in. (max/min)
• Across Corners (G): 0.354 / 0.331 in. (max/min)
• Head Height (H): 0.196 / 0.178 in. (max/min)
• Dimensional Standard: ASME B18.6.2

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