ISO 4017Hexagon headExternal hexagon

ISO 4017 M24 × 70 Hexagon head

ISO 4017 M24 × 70 is a hexagon head bolt with a 70 mm nominal length, on a M24 × 2 mm metric thread. ISO version of the full thread hexagon head screw. Head dimensions are dimensionally compatible with DIN 933 for the same nominal size.

Dimensioned drawing — ISO 4017 M24 × 70k 15L 70⌀39.98⌀24
ISO 4017 M24 × 70 — Hexagon headNominal dimensions in mm · Not to scale
Diameter24 mm
Length70 mm
Pitch2 mm
Socket size s36 mm
Head height k15 mm
HeadHexagon head
DriveExternal hexagon

Dimensions

Standard
ISO 4017
Type
Hexagon head bolt
Size
M24 × 70
Thread
M24 × 2
Length L
70 mm
Socket size s
36 mm
Head height k
15 mm
Drive
External hexagon
Head
Hexagon head

Nominal values in millimetres as published in ISO 4017. Estimated weight 248.588 g per piece in steel (250.171 g in stainless), calculated from the nominal geometry — real parts vary with tolerance and head chamfers.

DesignationM24 × 2 fine
Pitch2 mm
Nominal Ø24 mm
Pitch Ø22.7 mm
Minor Ø ext21.55 mm
Tap drillØ 22 mm

Other lengthsISO 4017 M24

All M24 specifications

Interchangeability

ISO 4017 is catalogued with DIN 933 as its equivalent designation. Dimensions are compared field by field rather than assumed identical.

Choosing and fitting this size

ISO 4017 M24 × 70 is a hexagon head in M24, 70 mm long under the head, on a 2 mm coarse pitch. Mating threads should be a matching class nut or a tapped hole of the same nominal size.

Common stock grades are 8.8, 10.9 and 12.9 in steel, plus A2-70 and A4-80 in stainless. Class 10.9 and 12.9 carry roughly 1.25 and 1.5 times the proof load of 8.8, but they also need a properly rated mating nut — a class 8 nut under a 12.9 bolt simply moves the failure into the thread. Zinc-plated 10.9 and above should be baked to avoid hydrogen embrittlement.

For a tapped hole, M24 × 2 mm takes a 22 mm tap drill, and the external thread's minor diameter is 21.55 mm — that is the section carrying the load, not the nominal M24 figure. Thread engagement of at least one times the nominal diameter is what lets the bolt fail before the thread strips.