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:
Batwing Side Plate, Weld-On
Product Details
Brand: Welder Series
MPN: 14120
Thickness: 3/16" or 3/8"
Hole size: 3/8" or 1/2"
Batwing side plate for axles that don't have the Ford perch pin boss. Holes are 1/2" diameter on 4-3/4" centers.
The 4-link brackets are 3/16″ steel. The hairpin bracket looks very similar, but has 3/8″ holes and is 3/8″ steel to mount a clevis.
The plate can be trimmed with a hole saw to fit your tube axle, or trimmed by hand to fit an I beam.