Chuck jaw carrier thread

[gregmcateer]

Hi folks,
I've rediscovered my long- neglected spare versa chuck jaw carriers for my axminster jaws.
Embarrassingly, the threads are corroded. I've cleaned and used wd40 to get them threading, but a couple of them will not go all the way down the thread, despite repeated screwing in and out with wd40.
So question- does anyone here know the size and pitch of tap I need to get to clean the threads out fully?
Many thanks in advance
Greg

 

[Dalboy]

I have just checked mine with my taps and the screws that attach the jaws to the carriers are 5 X 0.8 metric threads. Make sure that you check the tap and dies as there is also a 5 X 0.9

 

[gregmcateer]

Thanks, Derek.
That's really helpful
Greg

 

[Dalboy]

Make sure that you have not pushed any rust and other rubbish into the bottom as that will also prevent the screw from going in fully

 

[gregmcateer]

Yeah, thanks. I've been spraying wd40 and cleaning out the bottom with a little pin and a wire brush. To be honest, I might be pretty close now just patiently in and out with one of the screws.
If I did need a tap, I assume the size you described is 5mm diameter and the pitch is 8 ? So is that an m5, or am I misunderstanding?

 

[Dalboy]

Yeah, thanks. I've been spraying wd40 and cleaning out the bottom with a little pin and a wire brush. To be honest, I might be pretty close now just patiently in and out with one of the screws.
If I did need a tap, I assume the size you described is 5mm diameter and the pitch is 8 ? So is that an m5, or am I misunderstanding?

Yes an 5mm and a pitch of 0.8 pretty much a standard size

 

[gregmcateer]

Brilliant. Thanks

 

[J-G]

as there is also a 5 X 0.9

?????? I have to assume that that is a typo Dalboy. There is no Metric Thread standard that I've ever come across that includes 0.9mm pitch. There is a Löwenhertz Standard at 5.5 x 0.9 but that is a specialist thread form with a 53º8' flank angle used for measuring instruments (maybe no longer!). Both British and American Metric standards list 0.8 and 1.0. I no longer have the DIN standards to hand.

The 'Fine' thread series for 5mm Ø is 0.5mm pitch so that might be what you meant.

 

[gregmcateer]

Oh god! Do I need to start detailed study?!

 

[minilathe22]

If you want a second opinion I can check my Versachuch with a thread gauge tomorrow. With small sizes its easy to misread them. However if you look here:

Beaufort Ink - Versachuck spares

It appears there are different replacement screws, for different situations. Which suggests the thread is different.

 

[gregmcateer]

Thanks ml22. If you don't mind, that's great.
I'll take a look at BI, too.
Cheers

 

[J-G]

It appears there are different replacement screws, for different situations. Which suggests the thread is different.

Sorry - that doesn't suggest that the thread is different. The THREAD to attach jaws to carriers must be the same but the length or head size/shape may well be different. Of the four options offered, two are for Jaw Carriers and two are for back-plates and there may well be different threads between the two types.

 

[minilathe22]

I see you are correct J-G, the threaded section of the bolts must be the same to mesh with the jaw carrier thread.

 

[Dalboy]

?????? I have to assume that that is a typo Dalboy. There is no Metric Thread standard that I've ever come across that includes 0.9mm pitch. There is a Löwenhertz Standard at 5.5 x 0.9 but that is a specialist thread form with a 53º8' flank angle used for measuring instruments (maybe no longer!). Both British and American Metric standards list 0.8 and 1.0. I no longer have the DIN standards to hand.

The 'Fine' thread series for 5mm Ø is 0.5mm pitch so that might be what you meant.

No typo J-G here is two dies from a set and they definitely as stated and as you can see not from any cheapo type set either

 

[minilathe22]

I tried an M5 x 0.8 tap in my jaw carriers and measured the bolts with a thread guage, seemed to match that thread fine. Also the bolts tightened up again ok.

I don't see a reference to M5 x 0.9 anywhere, I wonder how that spec came to exist.

 

[gregmcateer]

Brilliant. Thank you all, gents
Greg

 

[Phil Pascoe]

?????? I have to assume that that is a typo Dalboy. There is no Metric Thread standard that I've ever come across that includes 0.9mm pitch. There is a Löwenhertz Standard at 5.5 x 0.9 but that is a specialist thread form with a 53º8' flank angle used for measuring instruments (maybe no longer!). Both British and American Metric standards list 0.8 and 1.0. I no longer have the DIN standards to hand.

The 'Fine' thread series for 5mm Ø is 0.5mm pitch so that might b

No typo J-G here is two dies from a set and they definitely as stated and as you can see not from any cheapo type set either

I have a '70s Kamasa set, U.S. made that has 5mm x .9 in it.

 

[J-G]

No typo J-G here is two dies from a set and they definitely as stated and as you can see not from any cheapo type set either

Interesting Derek - one never stops learning but they are certainly 'Specials' and of course there is no reason that any manufacturer should not make their product 'non-standard' just to maintain exclusivity - which begets increased profit It does seem a little odd that they are as you say 'Quality' but I think that 'Snap-On' are primarily aligned with the Motor trade and Car manufacturers are happy to 'lock in' customers to their components - not that I've ever been a cynic

I've also never seen 12 point Die-Nuts or even die-nuts which are 'adjustable' and I've been involved in Threads and the means of making them since before I was the 'Export Threading Department' at Herbert Small Tools (part of what was Alfred Herbert) in the 70's - though I have had some years out of that life!

 

[Dalboy]

I've also never seen 12 point Die-Nuts or even die-nuts which are 'adjustable' and I've been involved in Threads and the means of making them since before I was the 'Export Threading Department' at Herbert Small Tools (part of what was Alfred Herbert) in the 70's - though I have had some years out of that life!

I have only posted this as information.

The majority of dies have some sort of adjustment as they have a slit in them and the holder has three screws one fits into the taper where the slot is by tightening that you can slightly open the die the other two screws are also used in conjunction with the first to get the correct fit. You can also close the die by loosening the centre screw and tightening the two outer ones.
I have been using them for over 30 years in my trade
As for the 12 point I think that is a snap on design


The first image shows on the left one that can not be adjusted the one on the right can. The second photo shows the slit and three points that are used to adjust that type. The third is an adjustable die in the holder with the three adjuster screws.

These examples are from two other sets I seem to collect them having about 6 sets right down to the BA sizes also plenty of loose odd ones which where at the time needed for one off jobs

 

[J-G]

I'm sure you will guess that I'm very familiar with both solid and split dies but the information will no doubt be useful to others. It was the fact that the images were of Die NUTs which are generally used to repair damaged threads rather than manufacture from new so it is unusual to see them 'split' and fitted with what I imagine is a tapered grub-screw to make them adjustable. That is a very complex method and typical of 'Snap-On' to find a solution to a problem that didn't exist.

I have solid and split metric dies from M2 to M12 using the split die as wide open as I can get it as a first pass and finishing with the solid die which is naturally 'size'.

I also have BA Dies down to 12 - when I was an apprentice tool maker in the 50s/60s I remember handling 20BA dies !!!

My imperial taps & dies are a hodge-podge of items passed down from Farther which haven't got lost over the years during house moves!