Cable Clamps

Cable clamps hold a cable or a conduit rigidly, and that is what separates them from cable clips. A clip is a plastic saddle sized to a cable and fixed with a nail or an adhesive pad; a clamp is a metal or heavy-duty part that grips a cable, a pipe or a conduit and takes the load of the run. Where the cable is heavy, where it will be pulled, or where it has to resist vibration, a clip deforms or releases and a clamp does not. The clamp and tie-mount range is in tie mounts and cable clamps.

Clamp types and what each is for

A rubber-lined P-clip grips the cable jacket without cutting it and is the standard for a fixed run on a panel or a wall. A U-bolt clamp holds a conduit or a pipe by its outside diameter and is the heavy end of the family. A saddle clamp bears on the cable from one side only and is used where access is limited. In each case the part is sized to the outside diameter of what it holds, and the fixing hole size is separate — the two are often confused when a run is specified from a photograph.

Clamp or clip, decided by load and movement

A clip is adequate for a light cable, a short run, and a surface that will not be disturbed. A clamp is required as soon as the run is heavy, is subject to pull, carries vibration, or has to survive being stepped on or leaned against. The middle case — a bundle of light cables on a wall — is usually better served by a tie mount than by either, because the mount takes a tie and lets the bundle be dressed. The clip side of the family is covered in the cable clips guide.

When should I use a metal clamp instead of a clip?

When the run is heavy, will be pulled, vibrates, or carries a conduit. A plastic clip deforms or releases under those conditions.

How do I size a cable clamp?

To the outside diameter of the cable, pipe or conduit it holds — not to the conductor size. The fixing hole is a separate dimension.

Do cable clamps rust?

Zinc-plated clamps corrode outdoors and in damp interiors. For coastal or wash-down service, specify stainless.