T Nuts: What if any treatment?

[NigeParticipant @nige81730]

Looking to make my own T Nuts and wondering if they are just plain mild steel or are they hardened/tempered please?

[NigeParticipant @nige81730]

[VicParticipant @vic]

I've made T Nuts for a couple of mills over the years out of plain mild steel. Not heard of anyone hardening them before but you could do I suppose if you wanted to.

[NigeParticipant @nige81730]

Thanks Vic, I don't want to harden them, plain mild steel is ok by me if that's the usual

[John HaineParticipant @johnhaine32865]

If you tighten them enough for hardening to help, they will be too tight!

However, when I made some out of some square BMS bar, I started by milling down one dimension to suit, and when I took it out of the vice it had developed a banana-like bend due to stress relief! So you may find it a good idea (if you use BMS) to get it red hot for a minute or two and let it cool slowly before starting to machine it. Or use black bar.

[NigeParticipant @nige81730]

Thanks John. I have heard of BMS 'unstressing' when it is machined, Ill try for black bar when I come to it

[steamdaveParticipant @steamdave]

Posted by Nige on 05/07/2017 18:37:45:

Thanks John. I have heard of BMS 'unstressing' when it is machined, Ill try for black bar when I come to it

And bash the bottom thread with the ball of a hammer to deliberately damage it so that you can't run the bolt all the way through and possibly damage the slot.

Dave
The Emerald Isle

[AJWParticipant @ajw]

I tend to used a variety of studs in T nuts then run a washer and but on.

Alan

[Roger Provins 2Participant @rogerprovins2]

Made a handful by milling two corners of a strip of mild steel then chopped it into short lengths and drilled and tapped them.

Edited By Roger Provins 2 on 05/07/2017 21:13:19

[Mark RandParticipant @markrand96270]

If you make T nuts of the small size needed for Myford lathes and such, then hardening them can be useful to avoid thread tearout. I ended up case hardening all but one of the ones I made. Tthe other one didn't have any threads left…

[HopperParticipant @hopper]

I make my own, Myford size, and never harden them. No problems.

[Enough!Participant @enough]

Posted by Nige on 05/07/2017 18:12:21:

Looking to make my own T Nuts

 

Don't forget that you can turn T-Nuts if it's more convenient – stepped diameters; drill/tap; cut off; then mill flats on the larger dia. I generally find it less fiddly. Probably gets around any BMS distortion issue too.

If you don't mind interrupted cuts, you can even put flats on a length of bar, turn the barrel dia and part/saw off. Repeat as necessary.

Edited By Bandersnatch on 06/07/2017 01:28:51

[not done it yetParticipant @notdoneityet]

I have a dozen in a row at the moment, machined, drilled and tapped, waiting to be cut into separate pieces.

A dozen because my mill only has 12 1/2" traverse and they will be milled to ~22mm long (if the cuts are all square). There will be more as both mills use the same 3/8" size.

I would have preferred a hardenable steel as the threads would be less likely to get damaged (tight studding in the threads is a bear), but these are from black iron bar and I am likely not going to case harden them (my wife complains when I use the kiln for hours on end – no, every time I use it, if she knows!).

[Chris Evans 6Participant @chrisevans6]

If you use studs and not bolts in to the tee nut the life of simple mild steel will outlast you.

[Mark RandParticipant @markrand96270]

Posted by Hopper on 06/07/2017 00:16:55:

I make my own, Myford size, and never harden them. No problems.

Do you use 1/4" or 5/16" threads? I use 5/16" and there isn't much meat left on the top part of the nut at that diameter.

[Neil LickfoldParticipant @neillickfold44316]

I leave T nuts soft. I don't want them harder than the bed or slide they are being used on. If they wear over time, just replace or use helicoils to recover the threads. I make them fairly long to spread the load over the most area that is reasonably possible. Neil

[Martin KyteParticipant @martinkyte99762]

This site gives a clamp load of 700 odd pounds for a 1/4 inch bolt.

**LINK**

Myford boring tables are a little on the slender side so gently does it. Milling tables are much more robust.

regards Martin

[Mick B1Participant @mickb1]

All the industrial T-nuts I've used have been as hard as a landlord's heart. When I wanted to shorten one by a few thou to stop it projecting proud of the table and defeating a clamp, I had no option but to grind it.

I'd imagine gauge plate would probably work well unhardened for most ME uses, but I think you might need to remake MS ones quite often.

Edited By Mick Burmeister 1 on 06/07/2017 13:49:15

[VicParticipant @vic]

Posted by Bandersnatch

Don't forget that you can turn T-Nuts if it's more convenient – stepped diameters; drill/tap; cut off; then mill flats on the larger dia. I generally find it less fiddly. Probably gets around any BMS distortion issue too.

Yes, I've made them like that as well.

[Enough!Participant @enough]

I have to admit that I only ever make the "specials". I buy standard T-Nuts …. they are so inexpensive and I have more than enough jobs in progress and planned that the time can be better spent on.

Most of the ones I buy don't seem to be particularly hard. At least I've milled/filed them down for other purposes occasionally.

 

Edited By Bandersnatch on 06/07/2017 14:40:51

[NigeParticipant @nige81730]

Resigned to having to make T Nuts as I am finding it difficult to find them to fit my Myford ML4; all the commercially available 3/8 threaded ones seem to be too deep in the base as the bottom slot is only 5/32 'thick'. 8mm versions seem to have the same problem.

[Howard LewisParticipant @howardlewis46836]

Have never found mild steel to be a problem, either T section nuts, or a thinner disc with two flats, in the bottom of the slots. Have made lots.

After all the forces that you can generate with a 1/4 BSF or M6 will crack a Myford Cross slide (Anyone want the T shirt?) M8 and M10, being coarser pitch, are less likely to damage the table on a mill.

Ideally the nut should be just a few thou below the surface when pulled upwards, so that any distortion is minimal, and less than that to crack the material.

Howard

[John HaineParticipant @johnhaine32865]

My sense is that I never tighten Tee nuts/bolts/studs to anywhere near the point where a non-hardened thread is likely to strip; and if you are doing that then it's much too tight. And I've not had things moving on the mill table either.

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