M8 A2 Countersunk Socket Screws DIN 7991

Product Description

M8 A2 Stainless Steel Countersunk Socket Head Screws

M8 metric countersunk socket head screws manufactured from A2 stainless steel. These screws have a standard M8 × 1.25mm coarse metric thread, a flat countersunk head and a 5mm internal hexagon drive.

The countersunk head is designed to sit flush with or below the surface of a correctly prepared countersink. A2 stainless steel provides good corrosion resistance for general engineering, automotive, fabrication, maintenance and indoor or outdoor applications.

Product Details

• Thread size: M8
• Thread pitch: 1.25mm metric coarse
• Material: A2 stainless steel
• Head style: Flat countersunk socket head
• Drive type: Internal hexagon socket
• Hexagon key size: 5mm
• Nominal head diameter: 16mm
• Nominal head height: 4.4mm
• Available lengths: 12mm to 100mm
• Legacy dimensional designation: DIN 7991
• Related current standard: BS EN ISO 10642:2026

Length measurement: The length of a countersunk screw is measured over the complete screw, including its head.

Standards Information

DIN 7991 is the commonly recognised legacy dimensional designation for this screw type. The related current British and international specification is BS EN ISO 10642:2026, covering metric hexagon socket countersunk head screws with reduced loadability.

DIN 7991 and ISO 10642 should not automatically be treated as completely interchangeable because some dimensional requirements differ. Compliance with BS EN ISO 10642:2026 should only be claimed when the product dimensions, mechanical property class and supplier certification have been confirmed.

Countersunk socket screws have reduced loadability because of the combination of their head dimensions and internal socket. They should not automatically be treated as having the same head-load capacity as other screw-head designs with the same thread size.

Typical Applications

• Engineering assemblies requiring a flush surface
• Machinery, guards and access panels
• Automotive and motorcycle components
• Stainless steel fabrication
• Fixtures, brackets and equipment housings
• General maintenance and repair work

Installation Guidance

• Use a correctly fitting 5mm hexagon key or driver bit.
• Ensure the countersink angle and diameter suit the screw head.
• Keep the driver fully engaged to avoid damaging the socket.
• Select a tightening torque appropriate for the joint and materials.
• Consider a suitable anti-galling compound for stainless-to-stainless assemblies.

A2 stainless steel is suitable for many general-purpose environments. For prolonged exposure to salt water, swimming-pool chemicals or more aggressive corrosive conditions, an appropriate A4 stainless steel product may be preferable.

Specifications are provided as a guide. Where dimensions, thread coverage or mechanical performance are critical, please contact us before ordering.

Please Note: Specifications given are intended as a guide only. If critical to your project please check with us first.