Unhardened dowel pins

[R. Dan]

Hi everybody,

I need a Ø.500 (nominal) x 2.00 lg. unhardened dowel pin. It is to be used to fixture a weldment together and the root of the welds will be consuming part of the dowel pin (bevels on the plate being fixtured) so I would like to find something unhardened and a material that will be compatible with sub arc welding. The base of the weldment which the pin will be pressed into is 8630 forged steel. The tangs which are being fixtured and welded on are 2.25 thick HR Weldox 130 (900 mPA) plate. The only off the shelf dowel pins I have found so far are either 11L17 or 1215, neither of which I want to throw in the root of these weldments. I will use a standard hardened dowel pin if I have to but I haven't found a vendor yet who knows exactly what the material in those things are.

A standard Ø.50 dowel pin runs Ø.5002±.0001 size-wise. I want these kind of tolerances to make this work. Anyone know where I can find something like this? Plant production has already given me a reda$$ when I suggested they make the dowel pins themselves.

Thanks in advance

[Jaakko Fagerlund]

Why the hardened ones won't do? They are case hardened steel and the steel itself is either your run of the mill structural steel or the better one (like MC 212) that is intended for case hardening. Still weldable and requires nothing extra work.

[R. Dan]

Hardened ones will do. Need to be off the shelf because our fabrication personel are wrestling with this assembly right now. Fastenall has nice bright shiny ones on hand.

[Orange Vise]

The heat from the welding will temper them back significantly.

[wierdscience]

These guys list pins in 1018-
http://www.dowelspinsshafts.com/materials.html#stock

[Jaakko Fagerlund]

The heat from the welding will temper them back significantly.

The problem just might be fast cooling, which re-hardens the pin surface. Haven't really tested, all the pins I've welded have kind of been inside the weld and parts. Should some day test out by welding straight on the pin.

[DATo]

Why not just use standard 1/2" CRS and, if you are going to be doing a lot of these, a suitable reamer for the hole. Another thought might be to knurl standard 1/2" CRS to oversize it for a press fit. I'm not sure of how you intend to use this (press fit - slip fit etc) so it is hard to make an informed assessment.

[madokie]

check the shank od of bolts both metric and USA, maybe you'll find the right size, cut off hex and threads, and there you go.

[Jaakko Fagerlund]

check the shank od of bolts both metric and USA, maybe you'll find the right size, cut off hex and threads, and there you go.

Not straight nor round and tolerances are very open in bolts shank. Even cold drawn is better, but the thing is that cold drawn is usually h9 or h11 tolerance, meaning +0...-something. Dowels are usually m6 or the like, always on the positive side a little bit.

[John Stevenson]

Bolt shanks are usually way undersize as the threads are rolled.