H-STRUT General Fittings are designed to fit with all H-STRUT 1-5/8" wide channels. All H-STRUT fittings are manufactured from 1/4" thick carbon steel and are available in a variety of finishes. H-STRUT fittings have holes 9/16" diameter and are spaced 1-7/8" on center and 13/16" from the end.