M6-1.0 x 40 18-8 Stainless Steel Metric Flat Head Socket Cap Screw is selected for metric machinery when the fastener head should finish level with the surrounding surface after proper countersinking. This geometry reduces surface projection so guides, tracks, and mating plates can pass over the fastened area more cleanly.

Imported machinery maintenance often requires the exact metric thread and length instead of an inch-series substitution. Metric flat heads per ISO 10642 use a 90° countersink angle, while inch-series flat heads use 82°; the two styles do not seat properly in each other's countersinks. Confirm overall length, head diameter, head height, socket size, and key engagement before substitution.

For machine repairs, Cold Headers can help match the thread, length, material, and countersunk geometry rather than substituting by appearance. Alloy Steel Metric Flat Head Socket Cap Screws serve alloy-material metric prints.

Technical Highlights

• Head Style: Flat (countersunk), internal hex drive
• Countersink Angle: 90°
• Material: 18-8 Stainless Steel
• Thread Size: M6-1.0 (coarse metric pitch)
• Length: 40 mm (overall, including head)
• Head Diameter: 12.00 / 11.75 mm (max/min)
• Head Height: 3.72 mm (max)
• Hex Key Size: 4.0 mm
• Minimum Key Engagement: 2.16 mm
• Dimensional Standard: ISO 10642

Call 773-775-7900 or email Sales@coldheaders.com for pricing, availability, or a quote.