4-40 x 1/4 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 nylon insert helps resist loosening through friction at the mating threads, providing prevailing torque without requiring a separate locking component.
The button head profile offers reduced head projection, a smooth exposed appearance, and a broad bearing surface compared with a standard cylindrical socket head. Typical uses include machine guards, equipment covers, and service panels, where a precise socket fastener with a low rounded head can support compact machinery layouts. Review thread size, length, mating material, available drive access, and whether the nylon insert is appropriate before release to production or repair work.
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.
Technical Highlights
- Material: Alloy Steel
- Thread Size: 4-40
- Length: 1/4 in.
- Head Style: Button Head
- Drive Type: Internal Hex Socket
- Locking Feature: Nylon insert providing prevailing torque
Call 773-775-7900 or email Sales@coldheaders.com for pricing, availability, or a quote.
