Sta-Kon 18RA-38X EXP VYNL INS RNG TERM 22-18 RED

Use the ring, which is what the Sta-Kon 18RA-38X is. A closed ring tongue cannot vibrate off the stud if the nut backs off, so it is the required style on motors, equipment grounds, and anything subject to vibration. A fork terminal only makes sense where you need to slip the conductor off without fully removing the screw, like a terminal block you service often. Many panel and equipment specs prohibit forks outright for that reason.

Copper. That matters for two reasons: it is only rated for copper conductor, not aluminum wire, and it should land on copper or tinned copper hardware where you can avoid dissimilar-metal contact. Do not use it to terminate aluminum building wire.

Use a proper insulated-terminal crimper matched to the 22-18 AWG red color code. Vinyl insulated barrels like this one are crimped through the insulation in a color-coded nest, and pliers or a generic crimper will either under-compress the barrel (high resistance, pull-out) or split the vinyl sleeve. Most insulated crimp tools mark the 22-18 position red, which lines up with this terminal.

Order by manufacturer part number 18RA-38X from Sta-Kon. It is the red 22-18 AWG vinyl insulated copper ring terminal with the 3/8 inch ring. If the existing terminals in the panel are red with a large ring on a small conductor, this is the same part family; check the ring size stamped or measured on the old tongue, since the same 18RA series runs in several stud sizes.

The vinyl sleeve on the 18RA-38X insulates the barrel and covers the wire entry, but a plain vinyl insulated terminal is not a nylon or heat-shrink barrel and gives no sealing. On 22-18 AWG stranded wire that flexes, add a tie or clamp to take the strain, or step up to a heat-shrink insulated ring if the connection is exposed to moisture.

Country of origin on the 18RA-38X is the United States. That is usually the detail institutional and government procurement needs for domestic-sourcing requirements on a bid.