Sta-Kon RZ5 POLYCARBONATE INS RING TERM GRN M5

The RZ5 is sized for 0.25 to 0.75 mm2 conductor, which is roughly 24 to 18 AWG. It's a small-signal and control-wire terminal, so if you're landing anything heavier than 18 AWG you need the next barrel size up, not this one.

The ring is an M5, so it drops over a 5 mm stud or screw. On a terminal block or ground lug drilled for a #10 screw it will also pass, since #10 is close to 5 mm, but it will be loose on anything smaller and won't go over M6.

Green on a Sta-Kon insulated terminal is the wire-range code, not a ground marking. It identifies the 0.25 to 0.75 mm2 barrel so an inspector or the next tech can see at a glance that the right size was crimped. Don't read it as a ground-only part.

Polycarbonate is the stiffer, higher-temperature insulation choice compared with common vinyl terminals. It resists deforming and splitting when the crimp tool bites down and holds up better in panel and enclosure heat. For low-temperature, low-cost general wiring, vinyl is fine; for control panels and equipment where the terminal sits in heat or gets handled repeatedly, the polycarbonate body on the RZ5 is the reason to pick it.

The conductor barrel and ring are electrolytic copper, so you get copper-to-copper contact with the wire and no dissimilar-metal junction at the crimp. Copper still needs the joint kept dry or protected in a wet location, but electrically it's the right pairing for copper conductors.

It's an insulated barrel terminal, so it crimps with a standard insulated-terminal tool using the nest that matches the 0.25 to 0.75 mm2 range (the green station on most color-coded crimpers). An uninsulated-terminal die will crush the polycarbonate body, and pliers will not give you a holding crimp.

A ring like the RZ5 has to come off the stud entirely to be removed, which is exactly why it's used where vibration or a safety circuit makes a wire pulling loose unacceptable. A fork or spade slides out under a loosened screw, which is faster for service work but can back out. Pick the ring for motor connections, grounds, and anything that moves; pick the fork where you expect to be swapping wires often.

Order it as Sta-Kon RZ5. That single part number covers the green polycarbonate insulated M5 ring terminal for 0.25 to 0.75 mm2 wire, and it is manufactured in Sweden.