Steel bottom mount 1/4 in. rod hangers with 1/4 20 x 1 in. screw shank and No. 3 point for Purlins. Self drilling range 0.036 to 0.188 in.
Dottie steel rod hangers loaded perpendicular to the threaded rod (shear) the ultimate load capacity for the anchor is 1,965 lbs. in nominal 20 gauge steel (0.036 in.). Steel Dottie rod hangers are recommended to be installed with UNIB Universal Steel and Wood Nut Driver.