Mod Marv's Lantern vise

[Toolmaker51]

That shirt pocket increases! Now it carries loaves of bread?
Vee's of most sizes are more easily produced by cutting a relief before removal [or just before finishing depending on methods in play] Vee portion itself.
The relief keeps the 'corner' and side of the cutter from being engaged by material. Just flip part and run other edge; both sides now more alike than other means. A big deal when final finish is after heat treating etc.
Hack saw, band saw. circular blade, cutoff wheel, end mill...all applicable. Then with a little preparatory set up, symmetrical form is simplified. Also allows in milling/ grinding/ shaping using same cutting action to finish both sides, one at a time; avoids profiling one side while end milling other.