I think they are pretty unique to dialarcs from what I've read. I have one that I could unscrew if you need any details of the interior (not in a hurry!). PM me if you need it, as I'm unlikely to check back here. Al.
P.S. I have seen modern replacements from a company who make tig pedals for lots of different machines. Might find it on google if you're lucky. I think they were around 150 quid.
Hi - if its a HF E , its a rotary pot - 1 k , is its an older HF ( no E which stands for electronic ) its a 10 ohm wire wound pot. my company can supply either new - call 01562 748200 for further details - we manufacture them in house , not a cheap tacky import .
Regards
Matt Ball - Specialist Machine Parts kidderminster.