Bolt size please

[Ukastronomer]

PLEASE can anyone tell me what thread the standard screws on diagonals and the standard interface (for not knowing the right word) are

Thanks

I want to replace them with something longer with a larger head, I don't want to over tighten but they are never tight enough to hold a Quark

[Saturnine]

The Skywatcher focusers and diagonals that I have, the retaining screws are M4 X 0.7mm pitch. Have purchased replacement thumb screws for some, not necessarily from the sellers linked here. Just some examples.


https://www.ebay.com.au/itm/Kipp-Thumb-Screw-Knurled-M4-X-15-mm-L-Pack-2-Duroplast-Screw-Steel-K0141-04x15/172540169049?ssPageName=STRK%3AMEBI DX%3AIT&_trksid=p2060353.m1438.l2649

[Ukastronomer]

Great thanks

£3.95 UK. I hope

https://www.ebay.co.uk/itm/KNURLED-THUMB-SCREWS-STAINLESS-STEEL-HAND-GRIP-KNOB-BOLTS-M3-M4-M5-M6-M8-M10-/182019943325