fixing a silverline 4 inch vice?

i own a 4 inch vice by silverline.i have broken the screw underneath.it requires acme thread lead screw but iam unsure of it's size,if anybody could help that would be brilliant ta.
brighteyes9, June 2017


done
Amazon sell this vice for £16 post free - many people report the same problem as you mention.

One review says this...
ABSOLUTE RUBBISH!!!! SNAPPED IN HALF HAND TIGHTENING ON AN M10 BOLT. MADE OF CHEESE. Never again! Pay for better one

Good Luck..., June 2017