Blackburn FB4F12 FLEXIBLE BRAID 921.6KCMIL, 12 INLG

The FB4F12 is a flat flexible braid bonding jumper rated 921.6 KCMIL, 12 inches long, with a two-hole terminal pad at each end. It's the part you use to bond across a joint that moves or vibrates, or to carry a ground between equipment frames, bus, or enclosures where a solid conductor would fatigue. The braid construction is what lets it flex; the two-hole pads keep the connection from rotating under torque.

Overall length is 12 inches, measured as the cable length of the braid. That is a short jumper, sized for bonding across a bus joint, a hinged door or cover, an isolator, or a piece of equipment sitting on vibration mounts. If your span needs slack for real movement, measure the hole-to-hole distance you have to cover and leave a bend in the braid rather than pulling it straight, and step up to a longer braid if 12 inches would end up taut.

The conductor is tin-plated copper. The tin plating is there to resist oxidation and to reduce the galvanic issue you get when bare copper sits against aluminum, which is why tinned braid is the usual choice when you are bonding to aluminum bus or an aluminum enclosure. For an aluminum connection you still want the joint prepped and an approved joint compound used per the equipment instructions.

Flat braid flexes in the plane it is bent and takes repeated movement far better than a comparable stranded cable of the same ampacity, which is why it gets specified on vibrating machinery, expansion joints, and hinged panels. A stranded cable jumper with lugs is the simpler, lower-cost pick for a static bond that never moves. The FB4F12 is the flexible, flat-conductor version, so choose it when the connection will see movement or shock.

It is sold each, as one 12 inch braid with the two-hole pads formed on it. Bolts, nuts, washers, Belleville washers, and any joint compound are not part of the item, so pick those up separately to match the hole pattern and bus you are landing on.

Country of origin is the United States. Order it as Blackburn FB4F12, which is the manufacturer part number for the 921.6 KCMIL, 12 inch flexible braid. Institutional and government buyers working to a domestic-preference spec should reference that origin on the submittal.