dowel pins dimensional data

Precision Technology
Supplies Ltd

Technical Data

Dowel Pins - Tolerances and recommended hole sizes

Metric range

Diameter tolerances

Diameter	m6 (standard)	h8 (to order)
1-3MM	+0.002 to +0.008	0 to-0.014
4-6MM	+0.004 to +0.012	0 to-0.018
8-10MM	+0.006 to+0.015	0 to -0.022
12-16MM	+0.007 to +0.018	0 to -0.027
20-30MM	+0.008 to +0.021	0 to -0.033

Length tolerances

Length	length tolerance
3-6MM	+/- 0.24
8-10MM	+/- 0.29
12-18MM	+/- 0.35
20-30MM	+/- 0.42
32-50MM	+/- 0.50
55-80MM	+/- 0.60
90-120MM	+/- 0.70
120+ MM	+/- 0.80

All dimensions are in MM

Recommended hole sizes

Where an interference fit is required (as opposed to a sliding or clearance fit)
the dowel must be precision ground and the hole must be reamed.
The relationship between the diameter of the pin and the diameter
of the hole must take into account the ductility of the dowel and
the hole material and will vary more accordingly to this factor than
to the size of the dowel itself.

In hardened steel parts, the hole should be 0.005 to 0.008mm smaller
than the dowel. In unhardened materials, the hole should be 0.025mm
smaller than the dowel.

For dowels ground to m6 tolerance, the holes should be reamed to 25
microns smaller (5 to 8 microns for hardened steel) using the lower
limit of the m6 range as the reference point.

Imperial dimensions available on request

If the information you require is not in the above tables please us and we will be happy to send it to you.

This information is for guidance only no liability can result from its use