Grub Screw Solution Needed

I’ve lost a grub screw for my OBE cartridges. I seem to either lose them or round their heads from overtightening! I’m looking for a screw with a bigger head or deeper recess so that I don’t round them.

I’d try some M4 cap head screws in the same length, but I can’t find any stainless steel ones that are 6mm long. Has anyone switched out their screws for something more substantial?

https://www.ebay.co.uk/itm/HEAVY-DUTY-M3-M4-M5-SOCKET-BUTTON-SCREWS-Hex-Dome-Head-A2-Stainless-Steel-Bolts/202694497081?var=502807510782&hash=item2f31889339:m:mpruMGu4Fes8fQT46Z5sQ3g

Thanks, this could work. But I was hoping for a Torx version or one with a bulky head so it is easy to grip with pliers if it gets stuck.

Take a hacksaw to some M4 bolts?

M4 x 6mm Socket cap screws stainless steel
https://www.amazon.co.uk/Socket-Bolts-Stainless-Screws-Delivery/dp/B00C4D6HEY

M4x6mm 304 Stainless Steel Button Head Torx Screws Bolts T20 Drive 20pcs

https://www.ebay.co.uk/itm/M4x6mm-304-Stainless-Steel-Button-Head-Torx-Screws-Bolts-T20-Drive-20pcs/302341784310?epid=13002541876&hash=item4664f982f6:g:2JMAAOSwwQVc7uQp

Clerkenwell screws?

Thanks so much for your help. Those Torx ones on ebay look good for £2.15, except the delivery time is between 3 and 9 weeks :(
If I cut a M4 bolt will it damage the coating and make it likely to rust and get stuck?

Don't take this the wrong way, but if you're a bit prone to rounding Allen head bolts, then you'll definitely round out Torx ones. Figure out what you're doing wrong that is rounding out the hex. If it's as simple as you're not using the right size key, then get a new or better set of Allen keys. Just because it loosely fits in the hole, Imperial doesn't fit metric or vice versa. If it's a ball-ended key you're using and that's causing it to round out, then use a straight sided one. If you're leaning on the key and mangling the sides, then don't do that. Etc.

The Clerkenwell screws website wasn't working, but I've ordered some with threadlocking liquid already on them: https://www.accu.co.uk/en/torx-cap-head-screws/255956-SHC-M4-6-A2-R360

Thanks Jonny, it might have been the allen keys that didn't fit right and that I was over tightening them because I didn't want them to come loose.

As in the name, stainless steel is not a coating but a material combination. Cutting at normal temperatures therefore has no affect on the properties.

Sorry I assumed it would have some sort of coating on it aswell.

A Torx head can actually accept more torque for a given size bolt than a hex head .. as long as the proper Trox bit is used! The torx pattern has more bearing surface area to spread the tightening torque force over.

I'm not sure if its the type of stainless steel or the drive type (probably both), but these screws seem much less prone to rounding :)