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Socket Countersunk Head Machine Screws are made to DIN standard 7991 and host a hexagonal recess. They can be driven using a hex wrench or insert bit.
The driving of this screw with a hex wrench or insert bit makes these screws more efficient than slotted screw products, as the hex socket drive has more resistance to cam-out, and can be used alongside power drivers, enabling faster installation and higher torque to be achieved.
Available from Fastenright in Steel grade 10.9, in A2 and A4 Stainless Steel, and in Brass, Aluminium or Titanium if required.
As standard these screws are available from M2 to M36, with lengths ranging from 3mm onwards. Imperial and other threads (UNC, UNF, BSW and BSF) are also available.
Non-standard sizes and materials are available to order as specials, including custom parts made to drawings.
| Socket Countersunk Screw – DIN 7991 | |||||
| Thread Diameter | d2 (mm) | k max. (mm) | S min. (mm) | Pitch (mm) | Available Lengths |
| M2 |
4.0 | 1.2 | 1.27 | 0.40 | From 3mm |
| M2.5 | 5.0 | 1.45 | 1.5 | 0.45 | From 3mm |
| M3 | 6.0 | 1.7 | 2.0 | 0.50 | From 4mm |
| M3.5 | 7.0 | – | – | – | From 5mm |
| M4 | 8.0 | 2.3 | 2.5 | 0.70 | From 4mm |
| M5 | 10.0 | 2.8 | 3.0 | 0.80 | From 6mm |
| M6 | 12.0 | 3.3 | 4.0 | 1.00 | From 8mm |
| M8 | 16.0 | 4.4 | 5.0 | 1.25 | From 10mm |
| M10 | 20.0 | 5.5 | 6.0 | 1.50 | From 12mm |
| M12 | 24.0 | 6.5 | 8.0 | 1.75 | From 16mm |
| M14 | 27.0 | 7.0 | 10.0 | 2.00 | From 25mm |
| M16 | 30.0 | 7.5 | 10.0 | 2.00 | From 20mm |
| M18 | 33.0 | 8.0 | 10.0 | 2.50 | From 40mm |
| M20 | 36.0 | 8.5 | 12.0 | 2.50 | From 30mm |
| M22 | 36.0 | 13.1 | 14.0 | 2.50 | From 40mm |
| M24 | 39.0 | 14.0 | 14.0 | 3.00 | From 30mm |
| M27 | – | – | – | 3.00 | Please Call |
| M30 | – | – | – | 3.50 | From 50mm |
| M36 | – | – | – | 4.00 | Please Call |
