Thomas & Betts 22-16 AWG Ring Terminal

The RA18 series ring terminal takes 22 to 16 AWG stranded copper conductor, and the red nylon insulation is the standard color code for that range. Insulation OD on the wire can be up to 0.136 inch and still seat in the sleeve, so it handles thicker-jacketed 16 AWG as well as thin appliance wire.

Two ring sizes: #6 stud (RA18-6) and #10 stud (RA18-10). Pick by the screw or stud diameter on the terminal block, ground lug, or motor lead you are landing on, not by the wire size, since both cover the same 22-16 AWG range.

Thomas & Betts lists the WT2000, WT112M, WT145C, WT145A, ERG4001 and ERG4003 tools for these RA series terminals. The ERG units are the ergonomic hand tools; the WT dies are sized for insulated nylon barrels, which matters because an uninsulated-terminal die will split the nylon sleeve instead of forming a proper indent crimp.

Yes, 600V and 105 degrees C. That covers standard control panel and motor-lead work, and the nylon sleeve carries a UL 94 V-2 flammability rating. It is both UL and CSA recognized, and RoHS compliant.

Nylon takes abrasion and higher heat better than vinyl and holds up during handling in a crowded panel. On the RA series the nylon sleeve is backed by an inner bronze insulation grip that lengthens the flexing radius of the conductor and stops conductor creep out of the barrel, which is the usual failure on vibrating equipment. The sleeve is rated to 105 degrees C.

Use the ring style, like the RA18, where the connection must not back out under vibration: the ring is captive and cannot slide off a loosened screw. A fork or spade slides on without removing the screw, which is faster for service work on crowded strips but will walk off if the screw backs out. For motor leads, ground studs, and anything on equipment that vibrates, ring is the right call. The RA18 comes for #6 and #10 studs.

The barrel and tongue are copper with an electro tin-plated finish. Tin plating gives decent corrosion resistance and a low-resistance contact face against plated steel or brass studs, but these are not marine-grade sealed terminals: the nylon sleeve is not heat-shrink and does not seal out water at the wire entry. For wet locations, use an adhesive-lined heat-shrink terminal instead.

They ship in cartons of 100 with an order multiple of 100, so you buy in hundreds even though the unit of measure is each. Standard pack, no bagged or strip-fed presentation.

Tongue stock thickness is 0.030 inch, the C dimension is 0.25 inch and the M dimension is 0.74 inch. Check those against the spacing on your terminal block: on tight multi-point strips the tongue width decides whether two adjacent terminals touch.