WHY

[FAT-TOY]

  Have a 1983 Husky 250CR and its missing a nut from the swing arm.  So here's the question 'why' would they make a 12mm swing arm bolt and use a .1mm pitch thread for the nut?  I know the answer most give is so we have to buy the nuts from them  and pay a premium for them.  You can't get them through your local bolt shop because they don't keep them and they can't even find a listing on them.  But surely the profit they make on the few they sell must be offset somewhat by the extra they must pay for a non standard size thread in the first place.
                                                                                                                             Zane

[GMC]

Fine pitch threads are less likely to vibrate loose

[LWC82PE]

There will be places on the net where you can buy these nuts. Try places in US like Graingers, or McMaster Carr etc.

[Lozza]

  Have a 1983 Husky 250CR and its missing a nut from the swing arm.  So here's the question 'why' would they make a 12mm swing arm bolt and use a .1mm pitch thread for the nut?  I know the answer most give is so we have to buy the nuts from them  and pay a premium for them.  You can't get them through your local bolt shop because they don't keep them and they can't even find a listing on them.  But surely the profit they make on the few they sell must be offset somewhat by the extra they must pay for a non standard size thread in the first place.
                                                                                                                             Zane

why worry?
http://www.ebay.com.au/itm/12mm-12-x-1-0-Metric-right-hand-Tap-M12-x-1-Pitch-/250862816185?pt=LH_DefaultDomain_15&hash=item3a6896cbb9
LH
http://www.ebay.com.au/itm/New-12mm-12-x-1-0-Metric-Plug-Tap-left-hand-M12-x-1-/250862671642?pt=LH_DefaultDomain_15&hash=item3a6894971a


Tap and die
http://www.ebay.com.au/itm/Unimat-DB-SL-12-mm-X-1-MM-Tap-Die-Set-New-/110610847223?pt=LH_DefaultDomain_0&hash=item19c0eb95f7

[Slakewell]

Fine thread is less likely to come lose and also offer better tension adjustment which can be important on the swingarm.

[FAT-TOY]

 Already have the taps and die on order and hope they arrive as soon as tomorrow.  As far as the fine thread being less likely to come loose that make sense but the difference between 1.25 pitch and 1mm pitch, I dont know if it would be worth the trouble, obviously Mr Husqvarna must have thought it would.
                                                                                                      Zane

[LWC82PE]

Probably a Swedish thing. Ohlins uses 1.0 too.

[grouty]

Hmm..... we keep them in stock here.
12x1.00   3/4 A/F (1/4" or 6.3mm thick) They are stainless too.

Seem to be dead easy to get over here in the UK.

[lukeb1961]

When you have a quick look, ISO seems to show TWO sizes, but there are effectively THREE metric pitches in  use (superfine/extrafine, fine, coarse), but usually only fine and coarse. The superfine pitch is, as you surmise, is for high stress items. Not every metric size has superfine.  Some that do; 8,10,12,14,18,20mm

Husqvarna chose superfine (1.0)  for a sensible reason. Stronger under tensile loads.

Now why didn't the others use superfine? well cost, obviously...

[chrisdespo]

Try Blackwoods