Sta-Kon RA18-10FL INSNYL LKG FORK TERM 22-16 No10 RED

The RA18-10FL takes 22 to 16 AWG stranded copper conductor. That is the red color-code range on insulated terminals, so the red nylon sleeve is your visual check on the bench that you grabbed the right size. Anything heavier than 16 AWG will not seat in the barrel and will not crimp reliably.

It is built for a No. 10 screw or stud. The fork slot opens to pass over a #10 terminal screw without removing it, which is why these get used on terminal blocks, strips and device screws where backing the screw all the way out is a nuisance.

Yes, 600 V is the rating on this terminal, and it carries UL file E9809. That covers the usual 120 V and 277 V control and lighting work as well as 480 V motor control panel wiring.

The tongue on the RA18-10FL has formed tangs at the fork opening that grip under the screw head once it is tightened, so the terminal resists backing out sideways if the screw loosens. A plain spade will slide straight off the screw; the locking fork will not. For vibration-prone gear, control panels on equipment, rooftop units, motor controls, that retention is the reason to spec it over a standard fork.

A ring terminal is the most secure connection because the screw passes through it, but you have to remove the screw completely to install or service it. The RA18-10FL locking fork slides on under a loosened No. 10 screw and its tangs hold it in place, so it is the choice when you are landing a lot of control wire fast or servicing a crowded block. If a code or spec on your drawing calls out ring tongue terminals specifically, use rings.

The barrel is copper, so it is for copper conductor only. Crimping copper terminals onto aluminum wire creates a dissimilar-metal joint that corrodes and loosens; aluminum needs an AL/CU rated connector instead.

RA18-10FL is the manufacturer part number. Breaking it down: red insulation for 22-16 AWG, No. 10 stud, FL for locking fork. It is sold under the Sta-Kon line.

Nylon. The RA18-10FL uses a nylon insulating sleeve rather than vinyl, which stands up better to abrasion and to the heat found inside panels and near ballasts or drivers. Vinyl-insulated terminals are the cheaper option for benign indoor low-heat work; nylon is what gets specified for equipment and panel builds.

Country of origin on the RA18-10FL is the United States. That matters on Buy American and federal or institutional jobs where domestic sourcing has to be documented for electrical materials.