Metric and Imperial Screw Sizes
 

How different are they?
I got told by one person that the screw I am after is M2.5 (metric) and another guy said 0-80 (imperial)

I've never heard of a 0.80 screw. Imperial sizes are usually termed as #2, 4, 6, 8, etc. What's the screw for anyhow?

The thread pitch is going to be a bit off even if the diameter is close, but as skellyo said, imperial sizes are numbers below 1/4". If screwing into plastic, it won't much matter, but aluminum/steel pieces may get the threads chewed out. If we knew what is what for, we could probably help you out.

It is actually the small 4 screws holding the end on of the Neu Motors. I took the screw into a fasterner shop and they said 2.5 x 3 but couldn't get any screws that small. I asked Steve Neu how big the screws were and he said 0-80 (sorry I typed 0.80 in 1st post) They do exist - http://www.microfasteners.com.au/fas...ketScrews.html

Yep, that is imperial size 0, 80 threads per inch. That is a small screw

lol, yes very small but cost more than larger screws :neutral:

I just realised that the screws that hold the shock pinion on the shaft is 2-56 x 1/4" and the screw looked about that size so I thought I would try it on the motor and it fit but you could wobble the screw a tiny bit in the hole. But isn't 2-56 bigger than 0-80?