Right angle and parallel type clamps and heavy‑duty u‑bolts (with hex nuts) are for rigid, IMC and EMT, emt
Edge type clamps are for rigid conduit only
Appleton and O‑Z/Gedney "K‑clamps" are designed to secure rigid metal conduit, IMC or EMT. They can be used across, parallel or perpendicular to beam, channel and angle supports.