DIN 7, DIN 6325, DIN 7979D, ISO 2338, ISO 8734
Dowels are solid pins, usually precision ground to narrow limits to permit accurate fitting, they are traditionally used to hold parts together in a fixed alignment, relying on the tightness of fit to stay in place.
Some applications for solid pins require clearance or transition fits on at least one of the components to be fastened.
There are three factors that determine the size of hole needed:
Our range standardises on m6 tolerance, which corresponds to the ISO and DIN standards*. The m6 tolerance is a 'plus tolerance' range and is normally used for interference fits. Also available are the minus tolerance ranges, h7 and h8
|Hole material||Hardened steel||Mild steel||Aluminium / zinc / brass|
|Interference fit||Pin Ø less 5 microns||Pin Ø less 25 microns||Pin Ø less 35 microns|
|Transition fit||Pin Ø less 2 microns||Pin Ø less 5 microns||Pin Ø less 5 microns|
|Clearance fit||Pin Ø plus 25-60 microns||Pin Ø plus 25-60 microns||Pin Ø plus 25-60 microns|
When a dowel is interference-fitted into a blind hole, it increases the pressure of the air trapped in the hole. It is recommended that the dowel should have an air release flat ground along its full length to prevent the dowel being ejected under the pressure of compressed air, or bursting the component into which it is driven.
|Through hardened steel||100Cr6, WS 1.3505 hardened and tempered to HV 550-650|
|Mild steel, unhardened||WS 1.0718 (9SMnPb28)|
|Stainless a2||WS 1.4305 or 303S31|
|Stainless a4||WS 1.4571 or 316S11|