I just noticed that gauge I linked to is 60 degree metric, and 55 degree imperial (whitworth), so that's not a good "covers both common systems" thread gauge - that said, I did run into stupid Whitworth threads on some hydraulic fittings in the last few months, so it's ideal to have all 3 gauges on hand - 60 degree metric, 60 degree imperial, and 55 degree whitworth - you never know what crazy thread you might run into randomly.
I have the screw from an HP8664A, which I assume will be similar. Pan head, torx drive.
I checked it with various thread gauges, and if you're not looking closely (i.e. under a magnifier or microscope) you'd be inclined to say it's 42TPI, but under the microscope I can see 42TPI isn't correct - the screw gets every so slightly out of sync with the thread gauge over the length of the screw.
Checking the metric gauges, it meshes exactly with 0.6mm, so 搁别苍é别 is correct - it must be 3.5mm 0.6mm/thread
You should get yourself a set of thread gauges - they come in handy for all sorts of stuff, and they're not that expensive. $10 gets you one with both metric and imperial. They tend to have them in the hardware store if you want to go to a local brick and mortar store to get them, but they can be hard to find - usually tucked away in a dusty corner of the hand tool section somewhere.
Link here as an example, not an endorsement of this particular gauge (though the ones I have are very similar, but came with a tap and die set, and I got another set when I bought 'fishtail' gauges for threading on the lathe with a single point threading tool):
here is a thread
comparison and pitch charts for future info
搁别苍é别
On 3/18/25 9:21 AM, Cubdriver via
wrote:
For what it's
worth, here in the U.S. McMaster-Carr has M3.5 x 0.6 pitch
screws?
?
-Pat
?
> ------ Original Message ------
> From: setton@...
> To: HP-Agilent-Keysight-equipment@groups.io
> Sent: Tuesday, March 18th 2025, 06:07 AM
> Subject: Re: [HP-Agilent-Keysight-equipment] Threads for
screws on 8656 Siggen
?
If it's indeed M3.5 x 0.6, it's the same size as the
hardware used on the recent HP-IB connectors, the ones with
black screws (early HP-IB connectors used uncolored stainless
steel 6-32 American hardware). You can check for compatibility
with the screws on an HP-IB connector.
?
This is indeed a metric size, but a very unusual one which
is not easily found, even here in Europe. Very few hardware
vendors have them, one of them is here :
(no affiliation with them).
I hope this helps !
Joel Setton
