These are custom A108 steel u bolts domestically manufactured with rolled thread.  The picture shows the initial sample pieces made in plain ASTM A108 steel material for testing purposes, with the production order consisting of zinc plated version of the same part.  The lead time for these custom round u bolts is slightly longer than usual, at 6-8 weeks from order confirmation.  Material certs and cert. of conformance are available upon request and a rush order option is available if a similar u bolt is ever needed in a hurry.

The inside width is set at 1.01-1.04", taking into account the drawn out material for the rolled thread.  Inside depth is set at 1.84" and approximately .62" of thread is incorporated on each leg.