B-Line Eaton series fastener hardware and accessories, Engineered with tools to optimize performance, 1/4" x 1-3/4",Concrete screws

That's what the ACS-25-175F is for. It's part of Eaton's B-Line fastener line for electrical work, a 1/4 inch by 1-3/4 inch concrete screw that anchors strut channel, straps, clamps and box brackets directly into concrete or block with no expansion shield or plastic plug needed. Drill, blow the hole clean, drive it in.

Straight into the hole. A concrete screw like the ACS-25-175F cuts its own threads in a predrilled hole, so there's no expansion sleeve, no shield, no setting tool. That also means it can be backed out and the fixture removed without destroying the anchor point, which is why they get used on temporary bracing and on work that may be relocated. If you need a heavy sustained tension load, an expansion or adhesive anchor is the better call.

Each ACS-25-175F weighs .009 lb, so a box of 100 is under a pound of hardware. Count on two anchors per strut bracket or clamp point and space your supports to the conduit or channel schedule on the drawing; the screw weight is negligible against your hanger load takeoff.