5/16-18 x 2 1/4 18-8 Stainless Steel Flat Head Cap Screw with Nylon Insert should be ordered by total screw length because the head is part of the measurement. Overall-length measurement matters on countersunk joints because the head occupies part of the thickness stack. A countersunk head bears on the cone rather than a broad underside, so clamp load should not be treated like a full socket head cap screw.
This size is often reviewed for washdown covers, processing guards, and inspection doors when stainless material, a flush head, and locking friction are all specified. For a low-profile head without cutting a countersink, compare 18-8 Button Head Socket Cap Screws with Nylon Insert.
The 18% chromium and 8% nickel austenitic stainless material is commonly selected for general corrosion resistance, clean appearance, and ordinary washdown exposure. For supported flat head cap-screw requests, nylon inserts are installed in-house at the Chicago facility.
Technical Highlights
- Material: 18-8 Stainless Steel
- Thread Size: 5/16-18
- Length (overall - includes head): 2 1/4 in.
- Head Style: 82° Countersunk Flat
- Drive Type: Internal Hex
- Locking Feature: Nylon insert providing prevailing torque
- Nylon Insert Diameter (P): 1/8 in.
- Nylon Insert Location (N): 13/64 in. +/-1/2 pitch
- Head Dimensions: ASME B18.3
Call 773-775-7900 or email Sales@coldheaders.com for pricing, availability, or a quote.
