DIN 931Hexagon headExternal hexagon

DIN 931 M20 × 160 Hexagon head

DIN 931 M20 × 160 is a hexagon head bolt with a 160 mm nominal length, on a M20 × 1.5 mm metric thread. Same head as DIN 933 but with an unthreaded shank under the head. The plain shank carries shear load, which is why these are preferred for structural steelwork and machinery frames.

Dimensioned drawing — DIN 931 M20 × 160k 12.5L 160⌀33.53⌀20
DIN 931 M20 × 160 — Hexagon headNominal dimensions in mm · Not to scale
Diameter20 mm
Length160 mm
Pitch1.5 mm
Socket size s30 mm
Head height k12.5 mm
HeadHexagon head
DriveExternal hexagon

Dimensions

Standard
DIN 931
Type
Hexagon head bolt
Size
M20 × 160
Length L
160 mm
Socket size s
30 mm
Head height k
12.5 mm
Drive
External hexagon
Head
Hexagon head

Nominal values in millimetres as published in DIN 931. Estimated weight 394.584 g per piece in steel (397.097 g in stainless), calculated from the nominal geometry — real parts vary with tolerance and head chamfers.

DesignationM20 × 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 931 M20

All M20 specifications

Interchangeability

DIN 931 is catalogued with ISO 4014 as its equivalent designation. Dimensions are compared field by field rather than assumed identical.