Using M3 x25 cap screws instead of x20

I'm finding it somewhat hard to get cheap M3 x20 screws ( i'm on a budget ), the cheapest i've found them is £11 for a pack of 100 :/.
But, i can get 200 x25's for little over £3.

Just going out on a whim here, but would it be possiblle just to use the x25's instead? Surely if it came down to it i could just saw off the extra 5mm surely?

Ollie.

You won't have any problems for the most part, but the 25s will be too long to mount a motor to the standard brackets. You could cut them down or add spacers to take up the extra 5mm easily enough.

Thanks, that'll make my life easier

That's what I did with my M3-25's.

FWIW: Put a normal M3 nut on the bolt before you cut. After some cleaning up of the end of the bolt and the thread, you should then be able to remove the nut. The act of removing the nut will help clean up any remaining thread problems, without trying to get a nut correctly aligned to the bolt thread.

Note: I have seen people do this with a die cutter, using the die cutter to cut the thread on threads badly damaged after cutting the bolt and then grinding the end smooth/straight. They were much larger threads than M3 though.

Yep cleaning up the threads after a cut is something you should practice before doing it on something crucial- like driving it's not hard but still needs some skill

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Wooden Mendel
Teacup Firmware

Thanks for the info guys, just waiting for parts now. Not the best time to order them, but still a good start to 2011

Ollie Wrote:
-------------------------------------------------------
> I'm finding it somewhat hard to get cheap M3 x20
> screws ( i'm on a budget ), the cheapest i've
> found them is £11 for a pack of 100 :/.
> But, i can get 200 x25's for little over £3.
>
> Just going out on a whim here, but would it be
> possiblle just to use the x25's instead? Surely if
> it came down to it i could just saw off the extra
> 5mm surely?
>
> Ollie.

Try orbital fasteners listed on the BOM, I did the budget on there it's about £20 for all the fasteners.

Cheers

Try [www.modelfixings.co.uk] they are very good for odd sizes and prices are reasonable too.

Mike