I've been asked to source a few feet of 1.4 mm diameter grooved steel rod. For all practical purposes the size and groove depth match M 1.4 thread so some threaded rod will do just fine.

I can only find it in short lengths of brass which won't do. Does anyone know of a source in steel?

If not is it practical to make my own. Tracey tools can supply a die, E-Bay also offers a thread rolling head at a not impossible cost, but what material to use and where to get it from. Common piano wire will clearly be far too hard to thread.

I imagine stopping something that slender from twisting during the threading process will require care and creativity.

Thanks

Clive

Thanks for the advice gentlemen.

It's for something to do with renovating a harpsichord. The grooves that are important to retain the parts in wood so it doesn't need to be a screw in thread. The pieces need to be straight too, the ones that came out certainly aren't. I found the M2 studding last year. Acceptable then but considered oversize now the man comes to do the job.

After further searching it looks like 1.4 mm steel rod can be got from Hobby Holidays at about 50 pence a foot so I'll probably go with that. Tracy Tools have dies at £18 each so sticker shock shouldn't give him a heart attack.

Thread depth is 0.15 mm so I guess I'd need 1.25 mm steel rod to start with which seems pretty unlikely. Translates to 0.049" which is near enough 18 gauge (0.048" ) so thread rolling is possible if suitable material can be found.

No luck at component-shop, nearest kirschner wires from UK suppliers appear to be 1.2 mm which may not be enough to thread roll. Fascinating how much stuff I didn't know about can be found by asking here.

Clive

Edited By Clive Foster on 01/04/2022 22:36:19

Reckon Speedy Builder5 is right about what this M 1.4 rod is for. Certainly looks so from the sample "fit to this" parts I have. Interesting that brass has been found acceptable before as my man says it has to be steel.

Trying hard not to be sucked deeper into this job. Big difference between half and hour or so on t'net to unearth a "get it from here" and deep involvement in making it. Straightening wire is definitely about 4 steps too far. Would soft wire even be stiff enough to thread?

Looks like options are:-

1) die cut thread using 1.4 mm rod from Hobby Holidays and a die from Tracy Tools

2) thread rolling head and 1.2 mm kirschner wires, both off E-Bay

Interestingly that E-Bay thread rolling head is for bicycle spokes but 18 gauge spokes don't seem to be made.

I'll see what he says.

Clive

pgk pgk

Thanks for that. Looks like I do have an option for correct size to thread roll then.

1.5 mm fully threaded would be too large. Specific thread isn't important, its the grooves that matter as they help it hold in place.

Clive

Gary

Nice to know that such things go quite easily given reasonable care.

Clive

Bernard

Very probably knurling would do fine but probably even harder to arrange than threads on that diameter.

Clive