4-40 x 3/4 Flat Point Alloy Steel Socket Set Screw with Nylon Insert is intended for shaft locations where the screw must clamp without the deliberate indentation of sharper point styles. This point style is useful when the part may be loosened, slid, and reclamped during changeover or setup. Use the heat-treated alloy steel body with the nylon locking pellet where the application calls for mechanical fastening rather than stainless material.
OEM assemblies pairing flats on shafts with flat points use the mating geometry to spread contact across the seat. ASME B18.3 places flat point diameter in a qualitative band of about 0.55-0.62 times nominal screw diameter, so confirm the mating seat rather than substituting a sharp point.
Cold Headers can help identify the correct flat point alloy set screw when the drawing calls out a locking insert. Check thread size, length, socket size, pellet dimensions, shaft-flat condition, and surface-marking tolerance before substitution.
Technical Highlights
- Point: Flat (full bearing face)
- Material: Alloy Steel
- Thread Size: 4-40
- Length: 3/4 in.
- Drive: Internal Hex
- Hex Key Size: 0.050 in.
- Locking Feature: Nylon insert providing prevailing torque
- Nylon Insert Diameter (P): 1/16 in.
- Nylon Insert Location (N): 3/32 in., +/-1/2 pitch
- Dimensional Standard: ASME B18.3
Call 773-775-7900 or email Sales@coldheaders.com for pricing, availability, or a quote.
