When we ran a full service chassis fab/turn-key hot rod shop a number of years ago, it was always useful to have threaded things around to weld into the frame for some kind of mount, etc.
Here’s a list of all our threaded things for your reference:
Mustang II Boxing Plate; 1935-40 Ford car, ea
Product Details
Brand: Welder Series Inc.
MPN: 354004
Country/Region of Manufacture: Canada
Thickness: 3/16"
Price is for one plate. Laser cut from 3/16" pickled & oiled mild steel.