All, Having tried and failed to find some decent aluminium vice jaws, I’ve glued some aluminium plate to some Draper plastic-lined items (that lasted two uses). I’ll also press some rare earth magnets in there to supplement the pointless originals.

So Id like to put a V-groove along and down the centre of one half, to grip/centre bar.

Can I use a 45 degree chamfer tool for this, or will the central point just gouge the aluminium?

Thanks.

Went for your ideas in the end (not sure what to do with the plain magnetic ones that are now half finished!). Two advantages – they can't fall off at an inconvenient time, and also you can grip very small things right at the top edge without them pivoting themselves off the jaws. I had to make the countersinks bigger, and turn down the bolts to make sure they wouldn't touch any small diameter bar sitting within the centering grooves. Ideally they'd be aluminium screws I guess:

Also gave it a blow over with blue paint while I was at it.

Cheers.