Socket Head Cap Screw M10 × 40mm Stainless Steel A4 (316)

M10 × 40mm socket head cap screw in A4 (316) stainless steel.

An Allen key reaches the head straight down, so it tightens hard in a counterbore or a recess where a spanner would never fit. Standard grade is 12.9, which is why it dominates machine building. A4 (316) stainless is the marine grade — it holds up in salt air, chlorinated water and chemical wash-down where A2 will eventually tea-stain.

To prevent seizure, use scuff paste.

Typical uses

• Machine frames and guarding
• Die and mould assembly
• Motorcycle and performance work
• Anywhere the head must sit in a counterbore

Manufactured to DIN 912. Dimensions, thread form and head geometry follow the standard, so it interchanges with any other DIN 912 part of the same size regardless of who made it.