5/16-18 x 1/2 18-8 Stainless Steel Flat Head Cap Screw with Nylon Insert combines stainless material, internal hex drive access, and a nylon locking pellet. 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. Flat head screw lengths are measured overall, head included, so this listed length is the total installed screw length.

This size is often reviewed for packaging machinery guards, changeover plates, and transfer covers when stainless material, a flush head, and locking friction are all specified. Where strength matters more than stainless material, Alloy Steel Flat Head Socket Cap Screws with Nylon Insert may be the better route.

Slight magnetism from cold working can be normal for 18-8 stainless, so final material selection should reflect the assembly conditions. Since 1962, Cold Headers has helped distributors, repair teams, and OEM sourcing projects locate specialty socket products.

Technical Highlights

• Material: 18-8 Stainless Steel
• Thread Size: 5/16-18
• Length (overall - includes head): 1/2 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.