Sta-Kon RB1157M INS VIN FORK TERM 18-14 No.10 MYLAR

The RB1157M takes 18 to 14 AWG stranded or solid conductor. That covers the usual 14 AWG branch circuit and control wiring as well as the lighter 16 and 18 AWG leads found on controls, thermostats, and fixture whips. If you are terminating 12 AWG or heavier, this barrel is too small and you need the next size up in the series.

It is sized for a No. 10 stud or screw. The open fork slides under a loosened No. 10 terminal screw on a breaker, strip, contactor, or fixture block, so you do not have to pull the screw all the way out. On a smaller No. 8 screw the slot will be loose and the head may not fully capture the tongue, so match the stud size.

A fork terminal like the RB1157M is the fast choice for service work: the open tongue goes on and off without removing the screw, which matters on a crowded terminal strip or when you are troubleshooting. A ring terminal is the captive option, because the screw has to come out to release it, so it is preferred where vibration or an accidental tug could pull a conductor off the stud. Some specs and panel schedules require ring tongues for that reason, so check the drawing before you crimp forks.

Yes. The terminal carries UL file E9809, which is the Sta-Kon listing reference you would cite on a submittal or an inspection for a UL recognized insulated terminal.

Vinyl is the insulation on the RB1157M, and vinyl is the general-purpose material for ordinary panel, control, and device wiring. For high-heat terminations inside luminaire housings or against hot equipment, nylon insulated terminals are the usual step up because they hold up better to heat and abrasion. Keep the vinyl parts in normal ambient enclosures.

Use an insulated-terminal crimper matched to the color-coded size, and set it on the blue die for this one since the RB1157M is a blue 18 to 14 AWG terminal. A plain pliers or an uncalibrated tool crushes the Mylar-lined vinyl barrel and gives you a connection that will loosen. The crimp tool is not included with the terminals.

Blue is the standard color code for the 16 to 14 AWG range of insulated terminals, and the RB1157M is blue with a 18 to 14 AWG barrel. On the job it lets an inspector or the next electrician see at a glance that the right size terminal went on the conductor. Red is the smaller 22 to 16 range and yellow is the larger 12 to 10 range.

The barrel is lined with Mylar under the vinyl insulation. That liner backs up the vinyl where the crimp bites, so the insulation does not split or extrude off the barrel when you set the crimp, and it adds dielectric strength at the wire entry. It is the detail that separates a Mylar-lined terminal from a plain vinyl one.

Country of origin on the RB1157M is the United States, which is what a government, school district, or federally funded job will want on the submittal when domestic sourcing is part of the spec.