Author Topic: RE: Bolt for idler on a recumbent  (Read 518 times)

RE: Bolt for idler on a recumbent
« on: 20 February, 2021, 12:17:43 pm »
I'm looking for a bolt with the following dimensions:

70mm x 5mm 0.8mm pitch or 32 TPI fine not coarse thread and these I imagine seem to normally come with a shank.

Earlier today none of this made 1 iota of sense so I've had to swot up on bolts and I have googled but couldn't find a supplier. It's needed to fix an idler to the frame by passing a bolt straight through.

Any help would be appreciated.

LittleWheelsandBig

  • Whimsy Rider
Re: RE: Bolt for idler on a recumbent
« Reply #1 on: 20 February, 2021, 12:24:38 pm »
M5 x 0.8mm pitch is coarse thread. 0.5mm pitch is fine thread.

M5 coarse pitch bolts are pretty easy to find. https://www.fixaball.co.uk/products/m5-cap-head-socket-screw-a2-stainless-steel?variant=29234598051949
Wheel meet again, don't know where, don't know when...

Re: RE: Bolt for idler on a recumbent
« Reply #2 on: 20 February, 2021, 12:55:22 pm »
M5 x 0.8mm pitch is coarse thread. 0.5mm pitch is fine thread.

M5 coarse pitch bolts are pretty easy to find. https://www.fixaball.co.uk/products/m5-cap-head-socket-screw-a2-stainless-steel?variant=29234598051949

Hmmm I'm looking at a bolt which came with the idler kit (unfortunately the bolt supplied is too short but otherwise it would have fit, if that makes sense :) ) and the thread looks pretty tightly spaced. I've had to measure and it came out as 22mm of thread, 28 threads which comes out as 0.79mm rounded to 0.8mm pitch and according to my resources that's fine pitch and it really looks it.

Have a read here 'A word about fine and coarse threading'

I'd be interested to hear how you worked it out as being coarse thread.

Re: RE: Bolt for idler on a recumbent
« Reply #3 on: 20 February, 2021, 02:01:39 pm »
Like LWaB says - M5*0.5 is metric fine and M5*0.8 is metric coarse.  Take a look here: https://en.wikipedia.org/wiki/ISO_metric_screw_thread#Preferred_sizes

Re: RE: Bolt for idler on a recumbent
« Reply #4 on: 20 February, 2021, 02:48:29 pm »
Coarse being the standard...
If it ain't broke, fix it 'til it is...

Re: RE: Bolt for idler on a recumbent
« Reply #5 on: 20 February, 2021, 11:48:21 pm »
Like LWaB says - M5*0.5 is metric fine and M5*0.8 is metric coarse.  Take a look here: https://en.wikipedia.org/wiki/ISO_metric_screw_thread#Preferred_sizes

Gotcha, didn't realise it was linked to bolt diameter. Thank you folks  :)

Re: RE: Bolt for idler on a recumbent
« Reply #6 on: 20 February, 2021, 11:56:10 pm »
M5 x 0.8mm pitch is coarse thread. 0.5mm pitch is fine thread.

M5 coarse pitch bolts are pretty easy to find. https://www.fixaball.co.uk/products/m5-cap-head-socket-screw-a2-stainless-steel?variant=29234598051949

I'm learning and thank you for the link  :)