DIN 912Socket head (cylindrical)Hexagon socket

DIN 912 M3 × 30 Socket head (cylindrical)

DIN 912 M3 × 30 is a socket head cap screw with a 30 mm nominal length, on a M3 × 0.5 mm metric thread. A cap screw with a cylindrical head and internal hex drive. Because the head sits above the surface and the drive is recessed, it can be tightened hard and used in counterbores for a flush finish.

DIN 912 M3 × 30 — Socket head (cylindrical)Nominal dimensions in mm · Not to scale

Diameter3 mm

Length30 mm

Pitch0.5 mm

Socket size s2.5 mm

Head Ø dk5.5 mm

HeadSocket head (cylindrical)

DriveHexagon socket

Dimensions

Standard: DIN 912
Type: Socket head cap screw
Size: M3 × 30
Thread: M3 × 0.5
Length L: 30 mm
Socket size s: 2.5 mm
Head diameter dk: 5.5 mm
Head height k: 3 mm
Thread length b: 18 mm
Drive: Hexagon socket
Head: Socket head (cylindrical)

Nominal values in millimetres as published in DIN 912. Estimated weight 2.224 g per piece in steel (2.238 g in stainless), calculated from the nominal geometry — real parts vary with tolerance and head chamfers.

Thread data

Full M3 thread page

DesignationM3 × 0.5

Pitch0.5 mm

Nominal Ø3 mm

Pitch Ø2.68 mm

Minor Ø ext2.39 mm

Tap drillØ 2.5 mm

Other lengthsDIN 912 M3

All M3 specifications

M3 × 5 M3 × 6 M3 × 8 M3 × 10 M3 × 12 M3 × 16 M3 × 20 M3 × 25 M3 × 30

Interchangeability

DIN 912 is catalogued with ISO 4762 as its equivalent designation. Dimensions are compared field by field rather than assumed identical.

Equivalent standardISO 4762Hexagon Socket Head Cap Screw ComparisonDIN 912 vs ISO 4762Field-by-field differences and a substitution verdict

Choosing and fitting this size

DIN 912 M3 × 30 is a socket head (cylindrical) in M3, 30 mm long under the head, on a 0.5 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, M3 × 0.5 mm takes a 2.5 mm tap drill, and the external thread's minor diameter is 2.39 mm — that is the section carrying the load, not the nominal M3 figure. Thread engagement of at least one times the nominal diameter is what lets the bolt fail before the thread strips.