DIN 7991Countersunk head (90°)Hexagon socket
DIN 7991 M20 × 80 Countersunk head (90°)
DIN 7991 M20 × 80 is a socket countersunk head screw with a 80 mm nominal length, on a M20 × 1.5 mm metric thread. Flat head version of the socket screw. The 90° cone seats flush in a matching countersink so nothing protrudes above the surface.
Diameter20 mm
Length80 mm
Pitch1.5 mm
Socket size s14 mm
Head Ø dk36 mm
HeadCountersunk head (90°)
DriveHexagon socket
Dimensions
- Standard
- DIN 7991
- Type
- Socket countersunk head screw
- Size
- M20 × 80
- Thread
- M20 × 1.5
- Length L
- 80 mm
- Socket size s
- 14 mm
- Head diameter dk
- 36 mm
- Head height k
- 11 mm
- Thread length b
- 52 mm
- Drive
- Hexagon socket
- Head
- Countersunk head (90°)
Nominal values in millimetres as published in DIN 7991. Estimated weight 251.909 g per piece in steel (253.514 g in stainless), calculated from the nominal geometry — real parts vary with tolerance and head chamfers.
Thread data
Full M20 thread pageDesignationM20 × 1.5 fine
Pitch1.5 mm
Major Ø20 mm
Pitch Ø19.03 mm
Minor Ø ext18.16 mm
Tap drillØ 18.5 mm
Other lengthsDIN 7991 M20
All M20 specificationsInterchangeability
DIN 7991 is catalogued with ISO 10642 as its equivalent designation. Dimensions are compared field by field rather than assumed identical.