ISOscrewsHeadless

ISO 4028 Hexagon Socket Set Screw — Dog Point

ISO dog point counterpart, for positive axial location into a pre-drilled hole.

Dimensioned drawing — ISO 4028 M8 × 8L 8⌀4⌀8
ISO 4028 M8 × 8 — HeadlessNominal dimensions in mm · Not to scale

Where it is used

ISO 4028 is the dog point hexagon socket set screw, the ISO counterpart to DIN 915. A short cylindrical pin projects from the end and drops into a pre-drilled hole in the shaft, locating the part axially without marking the surface the way a cup or cone point would.

How to choose it

The dog point needs a matching hole: its diameter and the pin length are both specified, and a screw dropped into an undersized hole will sit proud and load the thread rather than the pin. Holds better than a flat point and damages less than a cup or cone, which makes it the usual choice for parts that are removed and refitted, such as collars and handwheels.

Dimensions8 sizes · millimetres

Thread dPitch P (mm)Socket size s (mm)
M30.51.5
M40.72
M50.82.5
M613
M81.254
M101.55
M121.756
M1628

Nominal dimensions in millimetres as published in ISO 4028. Tolerances, material requirements and marking are defined separately by the issuing body.

Available sizeslinked to individual specification pages

M30.5 mm pitch
M3 × 3M3 × 4M3 × 5M3 × 6M3 × 8M3 × 10M3 × 12M3 × 16
M40.7 mm pitch
M4 × 4M4 × 5M4 × 6M4 × 8M4 × 10M4 × 12M4 × 16M4 × 20
M50.8 mm pitch
M5 × 5M5 × 6M5 × 8M5 × 10M5 × 12M5 × 16M5 × 20M5 × 25
M61 mm pitch
M6 × 6M6 × 8M6 × 10M6 × 12M6 × 16M6 × 20M6 × 25M6 × 30
M81 mm pitch
M8 × 8M8 × 10M8 × 12M8 × 16M8 × 20M8 × 25M8 × 30M8 × 40
M101.25 mm pitch
M10 × 10M10 × 12M10 × 16M10 × 20M10 × 25M10 × 30M10 × 40M10 × 50
M121.5 mm pitch
M12 × 12M12 × 16M12 × 20M12 × 25M12 × 30M12 × 40M12 × 50M12 × 60
M161.5 mm pitch
M16 × 16M16 × 20M16 × 25M16 × 30M16 × 40M16 × 50M16 × 60M16 × 80

Thread referencesused by the sizes above

M3 × 0.5M4 × 0.7M5 × 0.8M6 × 1M8 × 1 fineM10 × 1.25 fineM12 × 1.5 fineM16 × 1.5 fine

Fitting and interchange notes

Interchangeable with DIN 915; shared body dimensions with ISO 4026/4027/4029. The pin is the locating feature, so the drilled hole has to be positioned and sized to suit — unlike a cup point, which will bite wherever it lands.