Replacement nuts for lathe chuck

Looking to replace the nuts that hold the chuck to the lather with flanged ones

Will stainless one be ok?

Edited By petro1head on 22/03/2023 12:47:52

One thing about those fiddly nuts behind the chuck is you want them to be easy to get off. Those kind of locking flange nuts may not be so easy. And stainless threads can tend to gall and seize up. I would stick with what the lathe manufacturer used.

Ideally from a strength point of view, particularly on a 5” or larger chuck, I would prefer steel nuts. Stainless nuts tend to have a lower yield, having said that I use M6 on my flange mounted chucks but only 100mmm. Also use plain flanged nuts if you want not the locking nuts shown in your photo, those will chew up the face with repeated release.

Flange nuts from a tee nut clamping system work fine for me.

Good idea

Zoro list Grade 10 flanged nuts as well as Grade 8 in BZP steel.

There are a number of sellers of Grade 8 BZP steel flanged nuts on Ebay (serrated or plain).

Nigel B

I use those, they’ve worked fine so far.

Grade 10 BZP flanged nuts [DIN 6923] are usually smooth rather than serrated. You might prefer that.

The black oxide flanged nuts that come in 58 piece clamp kits are usually non-serrated as well, and their height is usually more generous to get a spanner on, but still not as generous as a DIN 6331 flanged nut.

Unfortunately, DIN 6331 nuts are very expensive compared with the DIN 6923 variety.

You've probably got limited space behind the chuck, though, so extra nut height won't be wanted.

Edited By Bill Phinn on 22/03/2023 18:20:00

Flanged (Washer Faced) nuts will be OK, if there is room for the flange..

But NOT the self locking ones shown.

You do want to slacken them to take off the chuck at some time in the future, don't you?

The M6, 10mm A/F nuts are easy to drop.

Make up the extremely simple Widget designed my Danny M2Z. Very simple and effective.

Howard

I wouldn't describe a nut having a serrated flange as a self-locking nut, Howard. They're very easy to undo, even if they can leave marks on the surface of the clamped material.

Edited By Bill Phinn on 22/03/2023 18:22:19

It would be easy enough to skim the serrations off most of the flange nuts found on the web, me I'm still happy to use nuts and separate washers as Mr Warco intended

I use flange nuts on my WM250. It saves faffing about with nuts and washers in the very tight space, about 15mm, between the flange and the headstock.

Couldn't find smooth faced flange nuts so made a threaded mandrel and turned the serrations off. Mine are just bog standard BZP nuts. Seem to work quite well, I don't think they actually take much load, certainly not done up particularly tight.

John

Bill,

They may not be self locking in the sense that Nyloc ones are but rest assured that the serrations resist rotation for removal. We used similar bolts to retain Flywheel Housings, for exactly that reason!

And as you say, are likely to mark nthe surface, confirming a certain amount of digging in.

Such fixings ar eintended mfor clamping parts thatn are notb intended mto be separatedn frequently, if at all.

For clamping a chuk to a backplate, the friction between the threads should suffice is correctlyntorqued mup.

How mmany chucks come loose on the many mini lathes around the world?

Howard

Edited By Howard Lewis on 22/03/2023 18:54:08

I found some High Tensile Din 6923 steel ones with a flat back so have ordered them

I did exactly the same John, after reading your web page 😀

Tony

Is your lathe new?

No, 2007 vintage, more detail on Journeymans Workshop

John

From you photo it looks mint