Vise spreader - video

[Jon]

Vise spreader. By my mechanics insights. 12:18 video:

[Toolmaker51]

Threads are a versatile inclined plane; aka 'helix'. Still surprised when even a small thread generates significant force. Pushing a rusted vise open is decent proof. Good vises are tossed every day, saving and restoring usefulness is worth the effort.
Speaking of rust, it's said that a volume of rust is 7x that of the material 'consumed' to produce it. So, even parts that seem had clearance, it might not anymore!