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:
Tube; 7/8" OD x 1/2" ID x 2-1/4"
Product Details
Brand: Welder Series
MPN: 1080
Bolt Size: 1/2"
Diameter: 7/8"
Length: 2-1/4"
This tube keeps the frame rail from being crushed in a four link kit that mounts the bar on the outside of the frame rail. Also used in our universal rear Panhard kit.
Designed to weld into the frame rail for the upper bar in a front four link.