Dowel Pins

dowel pinsDowel pins are ground cylindrical pins primarily manufactured for precise locating devices in machinery and assemblies. Steel dowel pins are machined to tight tolerances with the DIN and ISO standard pins being m6 on the diameter. The corresponding holes are usually reamed to allow for a press fit, clearance fit or transition fit.

When designing engineered components, dowel holes are often used as reference points to control positioning alignment to attain repeatable assembly quality. When dowel pins are pressed into blind holes it is recommended that dowels with ‘air release flats’ are used to allow displacement of air preventing damage to the work piece or the ejection of the dowel.

Steel dowel pin standards include:

Metric Pins

  • BS 8734 / ISO 8734 A / ISO 8734 B limits
  • BS 8735 / ISO 8735 A / ISO 8735 B limits
  • ISO 2338A / ISO 2338A (stainless)
  • DIN 6325
  • DIN 7979
  • DIN 7

Imperial Pins

  • BS 1804 limits

All the DIN types listed below are available to purchase online at With catalogues available here or at Who Sells

Most commonly used in Construction, Aerospace. Automotive and Agriculture Engineering, and composites.

Dowel Pin Standards and Characteristics



ISO 8734 B Case Hardened Steel (except 1mm to 3mm) Domed and Chamfered
ISO 8735 B Case Hardened Steel – Internally Threaded (tapped) with chamfer
BS 1804 Hardened Steel Dowels – Internally Threaded (tapped) with chamfer
ISO 2338A Stainless Steel Stainless Steel (303/ A2) in Soft form with chamfer, chamfer.
DIN 6325 Fully Hardened Steel with dome and chamfer dome
DIN 7979 Fully Hardened Steel – Internally Threaded (tapped) with chamfer dome and air release flat.