Thomas & Betts 2520 1/2IN CORD CONNECTOR .125-.250 RANG

The 2520 grips cord with an outside diameter of .125 to .250 inch, so it suits small flexible cords like light-duty SO/SJ leads and fixture whips. Cord outside the .125 to .250 band will either not seal or not clamp, so measure the jacket OD before you order rather than going by conductor size.

It depends on the jacket, not the wire gauge. Measure the overall cord OD: the 2520 clamps .125 to .250 inch, which covers thin two and three conductor flexible cords but not heavier jacketed SO. Many 14/3 SJ cords run above .250 inch OD, so check with a caliper first and move up to a wider range grip if the jacket is oversize.

Both are cord grip connectors, but they land on different hubs and are made of different metals. The Thomas & Betts 2520 is a 1/2 inch straight cord connector with a .125 to .250 inch cord range, built in zinc die cast with a metallic finish. The Bridgeport Fittings RSR-2106 is an aluminum cord grip connector with a 3/4 inch NPT thread. If the box or fixture hub is 1/2 inch, the 2520 is the match; for a 3/4 inch NPT opening, the RSR-2106 is the one that threads in.

Zinc die cast, with a metallic finish. That gives you a metal body that bonds through to the enclosure when used with a locknut, which is what most commercial and industrial inspections expect over a nonmetallic grip.

The 2520 is a straight body, so the cord leaves the box in line with the hub. That is what you want for a top or bottom entry, a pendant drop, or a motor lead coming straight at the enclosure. If the cord has to turn immediately at the box, for example running up a wall off a side knockout, pick an angle style grip instead so you are not putting a sharp bend right at the clamp.

They do the same job - clamp and strain-relieve a round cord entering an enclosure - but the body metal differs. The Thomas & Betts 2520 is zinc die cast with a metallic finish; the Bridgeport Fittings RSR-2106 is aluminum. Aluminum bodies are commonly specified where the connector mates with aluminum enclosures or hubs to keep dissimilar-metal contact out of the assembly, while zinc die cast is the familiar general-purpose body. They are also different trade sizes, so the two are not drop-in interchangeable regardless of metal.