machining/custom nut creation?

[Thaco]

Hey all, just wondering if someone is in the biz and can help me out or point me in the right direction...

i need a nut that's threaded 3/8-24 unf but it needs to have a 12mm flat to flat measurement... everything i have found is 1/2 or 9/16 flat to flat, so i wasn't sure if it'd be cheaper/easier to just have a shop machine down existing nuts, drill out and re-tap a nut that's already 12mm flat>flat, or scratch create something..

I need 6 of them for now, i think that's the biggest hurdle, low quantity

[jwslam]

If you don't need metal, maybe try 3D printing?

[lilmira]

If you want exact thickness, you are gonna have to fabricate them. You can probably cut them from a coupling nut and re-tap the threads.

Otherwise, you can get jam nuts (lock nuts) which are about half as thick but they have less capacity since you get less thread engagement.

[gogreen]

How critical is the 12 mm measurement, and does it need to be within a certain tolerance for flatness or surface finish? Is appearance a concern?

You're looking at taking off 0.7mm if you go with the 1/2" flat-to-flat, so for a quantity of 6 I'm thinking you could take that off with a bench-mounted belt sander.

[AndyL]

Well ⅜ would have about a 14.2mm od - take a mm off each side with a file...

[Thaco]

Originally posted by gogreen
How critical is the 12 mm measurement, and does it need to be within a certain tolerance for flatness or surface finish? Is appearance a concern?

You're looking at taking off 0.7mm if you go with the 1/2" flat-to-flat, so for a quantity of 6 I'm thinking you could take that off with a bench-mounted belt sander.

yeah it doesnt have to be perfect, just unsure if it would be easier to do that or drill and retap an 8mm nut with a 12mm wrench size..

that's why i am trying to ask here if someone can or has done something like this.

also i guess i should have said it will need to be metal... aluminum would probably be alright. but i dont think plastic would cut it.

[Thaco]

ok i'll try shaving a nut that's already the right size threads, we'll see how it goes.. just wasn't sure if there was a better/easier way because having the hole center is somewhat critical.

[gogreen]

Sorry, I misinterpreted your original post. You said flat-to-flat and I was thinking nut thickness. That would be a little more work but could be done with a file and some patience.

Another option could be to source some hex bar stock in 12mm, part off short lengths, and tap it to the desired thread size.

[Graham_A_M]

^ yeah this or sand/file a 9/16 to the thickness you need is your best and cheapest bet. The latter would be the easiest, as i have no idea who in calgary would have that exact size of hex bar stock. Even so after you cut it, it'll likely still need to be filled somewhat to the exact thickness you need, as cutting each one to the 12 mill's each time will be next to impossible if doing it by hand repeatedly which you obviously will be.

I'd recommend using a caliper to make sure both sides of the nut are the desired thickness while your sanding or filing it down. At least that way you'll know if you have any high spots. As you file it down, you'll probably create burrs within the ends of the thread profile. So you may want to have a tap handy if you have one in that size. Otherwise I'd recommend threading the nut (about 3-4/5th the way) onto the end of a bolt, then as you think you're finished with sanding or filing one side of the nut down, thread it down the bolt. Doing that will use the bolt threads to clean out any burrs or sharp edges, thus making installing it on the desired bolt a lot easier. It'll also help you hold the nut in place while you sand or file it, but you may want to double nut the end so it's locked and doesn't move at all while you're working on it.

[Thaco]

i guess i could have explained it a bit better, i want the 12mm to be the "wrench size" the thickness doesn't matter too much

to make it easier, i stole this pic from the internets


the thickness isn't too important, but i need the "WAF" to be 12mm, and the threads to be 3/8-24 UNF

[Graham_A_M]

^ so the same thing would apply, just file the flats of the nut down from a 9/16" down to which you can use a 12 mill wrench to work on it.

You dont have to worry excessively about weakening the nut overly much as you won't be taking too much material off. The roots & thread flank of the thread and everything else will fail long before the body of the nut will in this case.

[Abeo]

Could you not just re-tap a JIS M8 nut to 3/8-24?

https://www.carbidedepot.com/formulas-tap-standard.htm
https://www.carbidedepot.com/formulas-tap-metric.htm

[Thaco]

Originally posted by Abeo
Could you not just re-tap a JIS M8 nut to 3/8-24?

https://www.carbidedepot.com/formulas-tap-standard.htm
https://www.carbidedepot.com/formulas-tap-metric.htm

that was soemthing i was considering, as per the OP, but going this route i am not too confident i could do this myself so i'd need a shop to do it. i have tried threading before, much smaller stuff, and failed horribly

[Abeo]

Originally posted by Thaco
that was soemthing i was considering, as per the OP, but going this route i am not too confident i could do this myself so i'd need a shop to do it. i have tried threading before, much smaller stuff, and failed horribly

You don't even need a machine shop for that. Just someone with a drill press, a good drill set and a tap. Use the existing hole as a drill guide, and use the drill press to centre the tap once you have the bolt the right size... then tap in a vice once the treads are started and aligned.

[Thaco]

yeah so i attempted this tonight, i got the 3/8-24 nuts, 9/16 wrench size, been messing with it for an hour, dremel, bench sander, file... ect... made it about .10 of a mm....

i don't have the patience for this, if anybody (who presumably has the proper tools) wants to do it for me i'll get you a box of beer or something...

need 6 nuts.

i know if someone with a lathe could re-tap some already 12mm wrench nuts, it'd take about 2 minutes to do all 6..

[Maxx Mazda]

Oh for christs sake it's not hard I make shit like this all the time. Buy some 12mm nuts, and drill the centre out, then tap with 3/8-24. I think I've made these exact nuts before actually.

[Maxx Mazda]

You don't need a lathe or even a drill press. A drill, a vice, and a tap are all that's required. When done, heat and quench to harden the threads and you're golden.

[78si]

Didn't bother reading... Pm Legendboy

[codetrap]

.

[Thaco]

Originally posted by Maxx Mazda
Oh for christs sake it's not hard I make shit like this all the time. Buy some 12mm nuts, and drill the centre out, then tap with 3/8-24. I think I've made these exact nuts before actually.

funny people raging at me saying "it's not that hard" yet nobody is willing to help

By the time i buy all the required tools... i could have just paid someone to do it and save my time. and i live in a condo, i don't have anywhere to put the tools when i'm done so it'd be a waste.