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:
Brake Plunger Tube
Product Details
Brand: Welder Series
Country/Region of Manufacture: Canada
Diameter: 5/8"
Thread: 3/8-24 RH both ends
Length: 22"
Tubing Size: 5/8” OD x .156” wall DOM
Used in our remote mount booster/ pedal bracket kit.
5/8” OD x .156” wall DOM