All-thread
All-thread turns up in 2 fields: fasteners, electricians. Here is what it means to the people in each one.
All-thread in fasteners
Shop name for threaded rod: steel bar threaded end to end, cut to length for hangers, anchors and long studs.
Rod threaded continuously along its whole length, sold in long sticks and cut to size on the job. Low-carbon zinc-plated rod hangs pipe, conduit, cable tray and duct from beam clamps and anchors, while alloy grades such as B7 serve as long studs on flanges and as anchor bolts. Cut ends need chasing, or a nut run off them, before a nut will start cleanly.
"Run three-eighths all-thread down from the beam clamps every eight feet and level the strut with double nuts."
All-thread in electricians
Steel rod threaded along its whole length, used to hang conduit, strut and fixtures from the structure.
All-thread is threaded steel rod, usually 3/8 or 1/2 inch diameter in 10 or 12 foot lengths, hung from beam clamps, concrete inserts or anchors to carry trapezes, conduit hangers, boxes and fixtures. It is cut with a rod cutter that leaves clean threads, and nuts and washers can be set at any height along it. Some crews call it ready rod.
"Drop two pieces of three-eighths all-thread from the beam clamps and we'll hang the rack at nine feet."