Screw queston (DIN933 / DIN912)

Mostly Printed CNC - MPCNC Advice
1

Hello,

is there any advantage using DIN933 bolts/screws over DIN912?

DIN933: https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcT2aB-rYfmpbT7FmhktjkWAw4UUAFusRCQlCoUBQpSuFf9k54lJxA
DIN912: http://titanwerk.de/WebRoot/Store6/Shops/2d839dab-8771-43ec-a5a6-f5215233c652/5513/B29E/F501/E069/96E4/0A48/3525/5C28/909001329650_m.jpeg

Do note the head of DIN912 is a bit higher.

E. g. in certain places theres not enough space to tighten the screws with a allen key or something like that?

Also, I have a hard time finding one of those M8 x 25mm coupling nuts in Germany (found only a 30mm so far). Should it work to just stack a bunch of common M8 nuts?

EDIT: I just figured the coupling nuts is only needed when threaded rod is used. I ordered leadscrews.

2

Smaller head means a washer is a good idea and yes a few places are tight.

3

So I went for the looks and used DIN912 screws for everything.

There’s just one (well, two actually) places where the larger head of those screws don’t fit, that’s where one will need something more flat. See pictures attached if anyone is interested in using those DIN912 screws for the MPCNC.

Also I had to file the brass thingy of my leadscrew abit (on both sides, top and bottom).

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