This is a basic design of those speed vice handles that you can get from MSC, ebay, Amazon, etc. They usually cost anywhere from $20-40 USD for one made from aluminum. Some people choose to design one and machine it themselves since they are so simple.
I designed one that i could just print myself for convenience if i wanted one. I have printed a test version in PLA for testing only. If i decide to print a functional copy i would probably print mine out of 100% infill of Nylon, but that's me.
p.s. i just tweaked the screw threads a bit to fit better. If you have problems please let me know. This was designed using a thread of 7/16-14 UNC. This is designed to fit a standard U.S. 3/4" Kurt vice with a hex shape.
When printing the handle you need supports, and i recommend using the brim feature in Cura's full settings since it is so tall.
If i were to print a functional version of this i would try 100% nylon.