Cutting thread on brass rod

[ucoulddoit]

Making steps for our kitchen using some reclaimed mahogany and struggling to cut the threads on a 10mm brass rod to support the folding top step/platform. Is brass usually more awkward to thread than than steel? Years since I've done this sort of metalworking and only had a brief go at it last night. Have chamfered the end of the rod and maybe need to do it a bit more. Any suggestions?

 

Andrew

 

[roys]

Brass is usually ok to thread, bit flakey compared to steel but usually cuts a good thread.

Chamfer a lead in like you said, the die that you are using makes a huge difference, a cheap die is only ever good enough for dressing up a damaged thread in my experience, a good quality die it should cut without much problem.

Where area are you in Scotland?

[Dan Maynard]

I'd say brass can be funny stuff, not worked too much of it but the different grades are markedly different to try to cut.

 

Also check the rod diameter, if it's 10mm nominal but actually a few tenths of a mm over this makes a huge difference to the work the die has to do. I suspect you may have a cheap die there, a good one will be split so you can adjust slightly, and start with it as open as possible to give lighter first cut.

[Dan Maynard]

Also, if you know anyone with a lathe you could buy a beer for, it's about a hundred times easier to put bar in a lathe chuck and use tailstock die holder.

[htb]

As mentioned check rod diameter and split dies are easier. IIRC do you not lubricate brass with paraffin when cutting threads?

[ucoulddoit]

Thanks for all the replies. I checked the rod diameter with a vernier gauge this morning and it looks to be spot on 10mm. It’s a new tap and die set from Machine Mart, first time used, but I suppose you get what you pay for! I’ll persevere and post an update in due course.

 

Andrew

[Macpherson]

+1 for the spilt HSS die otherwise it's very hard to get started and I'd say a decent cutting compound but I suppose engine oil would do.

Maybe rather than the chamfer you could give it a little bit more of a taper and you'll have to push down quite hard to get it started and once you get going give it small turns and back rather than just going for a single cut, good luck. 

[GarethM]

It's been a while since I've done it, but if you sand a longer taper over say 1" you can slowly work you way upto the full diameter.

 

It's going to be a pain regardless, I'd just find a local machine shop and they'll do it for a tenner if you're nice and pay cash.

[Bunzena]

Lubrication.

[GarethM]

I'll bite, everything is better with lubrication.

But real men use spit or nothing!.

 

And none of this dihydrogen monoxide stuff, people drown everyday you know!.

Edited August 8, 2022 by GarethM