ISO 4029HeadlessHexagon socket

ISO 4029 M3 × 4 Headless

ISO 4029 M3 × 4 is a socket set screw with a 4 mm nominal length, on a M3 × 0.5 mm metric thread. ISO equivalent of DIN 916, same cup point geometry and socket sizes.

ISO 4029 M3 × 4 — HeadlessNominal dimensions in mm · Not to scale

Diameter3 mm

Length4 mm

Pitch0.5 mm

Socket size s1.5 mm

HeadHeadless

DriveHexagon socket

Dimensions

Standard: ISO 4029
Type: Socket set screw
Size: M3 × 4
Thread: M3 × 0.5
Length L: 4 mm
Socket size s: 1.5 mm
Drive: Hexagon socket
Head: Headless

Nominal values in millimetres as published in ISO 4029. Estimated weight 0.222 g per piece in steel (0.223 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 lengthsISO 4029 M3

All M3 specifications

M3 × 3 M3 × 4 M3 × 5 M3 × 6 M3 × 8 M3 × 10 M3 × 12 M3 × 16

Interchangeability

ISO 4029 is catalogued with DIN 916 as its equivalent designation. Dimensions are compared field by field rather than assumed identical.

Equivalent standardDIN 916Hexagon Socket Set Screw — Cup Point ComparisonISO 4029 vs DIN 916Field-by-field differences and a substitution verdict

Choosing and fitting this size

ISO 4029 M3 × 4 is a headless in M3, 4 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.

Set screws are rated by surface hardness rather than tensile class — the common stock grade is 45H, which is hard enough to bite into a hardened shaft. Stainless set screws are not through-hardened and will not bite the same way, so they are a poor substitute where the point has to grip.

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.