4-40 x 3/4 Alloy Steel Button Head Socket Cap Screw with Nylon Insert is a socket-driven fastener for assemblies that need a rounded low-profile head plus a built-in prevailing-torque feature. The insert provides a prevailing-torque feature while preserving the compact top-side tool access expected from an internal hex button head screw.
Button head geometry is useful when clearance, appearance, and lower head height matter more than using a standard socket head cap screw profile. In packaging machinery, conveyor equipment, and production cells, the internal hex socket drive allows tool access from above while the nylon insert adds frictional resistance at the threads. Selection should account for joint geometry, thread engagement, installation access, head clearance, and the desired level of prevailing torque.
Cold Headers has supplied specialty socket fasteners since 1962 and supports exact-size sourcing for difficult-to-find socket products. For adjacent selections, buyers often compare standard Alloy Steel Button Head Socket Cap Screws, Alloy Steel Socket Head Cap Screws, and Alloy Steel Flat Head Socket Cap Screws when checking head style, material, locking feature, thread size, or nearby lengths.
Call 773-775-7900 or email Sales@coldheaders.com for pricing, availability, or a quote.
