1-8 x 5/8 is a square head machine set screw for assemblies that need point-style selection and direct wrench access.

Typical applications include retrofit work where the mating hole, flat, or seat determines the point style. 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 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 Headless Set Screws are the related headless option when flush-fitting screwdriver 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: 1-8 (UNC)
• Thread Fit: 2A (per ASME B18.6.2)
• Length: 5/8 in.
• Width Across Flats (F): 1.000 / 0.974 in. (max/min)
• Across Corners (G): 1.414 / 1.337 in. (max/min)
• Head Height (H): 0.774 / 0.726 in. (max/min)
• Dimensional Standard: ASME B18.6.2

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