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[AES]

Thanks Brian, looks very good/workable.

Again I really don't want to "teach granny to suck eggs" but on my vice anyway, I'm far from sure the material is cast aluminium. More likely it's pressure die cast "monkey metal" (e.g. a lot of zinc n other bits of soft scrap). If so, that means that the metal is likely a bit more "granular" than cast ali would be. In turn that means that when tapping your holes you must be very careful to keep clearing the swarf out of the holes - every half turn at least. Otherwise you can easily strip the thread as you're cutting it - just like over tightening the bolts after the threads are cut.

And use a lubricant - paraffin, or WD40 will do fine.

Again, sorry if this is stating the obvious, only trying to help, a 4mm thread is pretty fine, even the ISO standard "Coarse". Best of luck to Ruth!

 

[Claymore]

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[digerman]

something to think about drill two holes through the part that the vice grips to take dowels then cut in half fix dowels to one half and the other half will slide on them

 

[AES]

Good idea digerman.

AES

 

[digerman]

stuck this together today 120 mm diameter cut a bit of the front so handle can turn rite round
center 30 mm square x100 mm cut through the middle make sure the dowels are wider apart than the jaws
this should give 20 mm of movement
i used a 100 mm nail halved for the dowels