I tracked down the part number for a Torx variety of the cover retaining
screw: 0515-1245. This is directly orderable from the Keysight parts
store:
The price is pretty outrageous, but it's there if you need it. The
retaining ring (0510-0043) is also orderable, though this is less useful
as you should be able to just reuse the one from the existing screw.
A bit more background:
As far as I can tell, HP used two different types of screws to fasten
top/bottom covers to the rear chassis of an instrument: 6-32 0.46-in and
M3.5x0.6 12mm-LG. I have seen the M3.5 come in Phillips and Torx and the
6-32 only in Phillips. I checked a number of my instruments and the M3.5
seems to be a lot more common than the 6-32. The 0515-1245 mentioned
above is an M3.5 screw.
I'd previously investigated modifying existing screws for this purpose
but I don't think that's possible. The OEM screws have a thicker
diameter in the region where the slot is cut than normal screws. Even if
you got something to work I'd expect you would just end up with weak
screw. But someone who knows more about this sort of thing can weigh in.
I use the Jonard Tools CS-1022 for replacing this screw-retainer ring
assemblies:
It works great.
Hopefully someone else finds this useful.
Matt
PS I reached out to Torx Products a while back about this and they
claimed to have no knowledge of P/N 920-46590-570. That could be just
due to poor internal records. I ordered a few of the 0515-1245 and IIRC
they came from Singapore. I'll see if I can find a company name.
