Putlog Coupler

A putlog coupler is a single (half) coupler used to connect transom (the short tube that carries the platform boards) to a ledger (the long horizontal tube running parallel to the façade). In traditional bricklayer’s or “putlog” scaffolds, the transom spans from the ledger toward the wall; the putlog coupler clamps that transom to the ledger, stopping any slip or rotation and keeping the platform stable.
What it looks like: compact, lighter than a right-angle (double) coupler, with a single clamp body and bolt. It’s designed for one tube only, not for connecting two tubes at once like a double coupler would.
Bottom line: the putlog coupler is the platform keeper—it keeps the transom (and the boards on top) locked exactly where they should be.