Machine screws for Nova Chuck

[NOTTNICK]

I have lost a couple of the machine screws that hold the jaws on my Nova chuck.
They are 10mm M6 Countersunk Allen bolts with 10mm diameter heads.

Every one I find online has a 12mm diameter head.
I ordered some (in ignorance) and of course they sit proud as they wont seat all the way.

Does anyone have any suggestions where I might look?

I could get original Nova ones but they are £12.55. That seems like quite a lot to pay. Or is that all there is?

Thanks

Nick

 

[marcros]

Seems a lot but inkeeping with the price I was quoted recently for my record power chuck.

 

[lurker]

Can you mount 12 mill one in your lathe and use a metal file to remove the 2 mill ?

 

[Phil Pascoe]

Stick your 12mm ones in a battery drill and spin then against a grinder wheel taking the sides off until they fit. Doesn't take a few minutes.

 

[CHJ]

Annoying example of Brand tying you into non-standard bits to maximise profit.
I'm fortunate that standard 6mm CSK socket screws fit my chuck accessories.

I use the screwfix 16 (6197T) and 25mm (2398T) stainless versions, cheap as chips.

As long as the protrusion is not a problem I'd be tempted to just mount them in a spinning chuck and reverse bevel the sharp top edge with a fine file to improve the safety.

 

[Dave Brookes]

Try AHC(Camberley) 01276 709069, they stock an amazing range of screw fasteners.

Dave

 

[Duncan A]

Charnwood Nexus chuck jaw screws are smaller head dia than the equivalent Robert Sorby Patriot jaw screws, and have a slightly longer thread. Since these are Nova jaw compatible chucks I'm pretty sure a set of the Charnwood screws would do the job for £3.50.
PartNum N3JS
https://www.charnwood.net/product-searc ... _pathway-2.
Or just grind the heads of the standard screws as others have suggested.
Or drill out the jaw counterbore to accept the larger heads - they'll still be fine for the smaller screw heads.
There was a thread about this a few years ago and someone gave a link to a source of suitable machine screws but blowed if I can find it now.
Duncan

 

[NOTTNICK]

Thanks everyone
I put the oversize screw in my drill and spun it reverse against my spinning grindstone.
Job done, as long as I use it on the outside of the chuck (as it is well recessed).
Cheers
Nick

 

[LaymarCrafts]

Beware the cheap as chips Stainless Steel option the screws used on chucks are High Tensile Steel as a precaution against shearing.

Flying Jaws are lethal.

Richard

 

[The Tallest Turner]

It is also not only the diameter of the head, but also the pitch angle of the countersink...so you may find that even by reducing the diameter, only the shoulder is providing any downward pressure.

It is worth pointing out to owners of all these chucks (Patriot, Nova, Record), that these screws are of a special design and are NOT to the standard ISO design for countersunk socket screws. Standard ISO countersunk socket screws will not correctly fit the recesses in the jaws of these various chucks and should NOT be used. The use of these special screws is neccesitated by the very restricted space available on the mounting surface of the chuck jaws...