Look at pipe hanging hardware.
Don't know if these would lock good enough.
https://www.grainger.com/product/GRAINGER-APPROVED-Split-Ring-Hanger-WP153278/_/N-qv7?breadcrumbCatId=3427&s_pp=false&picUrl=//static.grainger.com/rp/s/is/image/Grainger/22FP62_AS01?$smthumb$
Or these with a U bolt.
https://www.grainger.com/product/GRAINGER-APPROVED-Rod-Hanger-Plate-WP153277/_/N-qv7?breadcrumbCatId=3427&s_pp=false&picUrl=//static.grainger.com/rp/s/is/image/Grainger/22FP85_AS01?$smthumb$