This document describes the application, wire range, maximum recommended current, and material characteristics of the SCOTCHLOK�557 IDC Electrical Tap Connector.
The SCOTCHLOK™ 557 is an IDC electrical tap connector designed to join two wire ends while providing insulation. It is suitable for 22‑16 AWG solid or stranded copper conductors and is commonly used with thermoplastic insulated wires such as T, TF, TFF, and others.
The data sheet lists construction details (tin‑plated brass U‑contact, flame‑retardant polypropylene insulator), electrical ratings (up to 600 V building wire, 1000 V for fixtures, 105 °C temperature rating), and maximum recommended currents for each wire gauge. Installation instructions emphasize turning power off, fully inserting unstripped wire, pressing the U‑contact flush, and latching the hinged cover. The connector is UL Listed and CSA Certified.
| Wire range | 22‑16 AWG (0.5–1.0 mm solid, 1.5 mm stranded) |
|---|---|
| Maximum current (22 AWG) | 3 A |
| Maximum current (20 AWG) | 4 A |
| Maximum current (18 AWG) | 7 A |
| Maximum current (16 AWG) | 10 A |
| U‑Contact material | Tin‑plated brass, 0.02 in thick |
| Insulator material | Flame‑retardant polypropylene, red |
| Weight | 0.030 lb (1.37 g) |
| Temperature rating | 105 °C |
| Certifications | UL Listed, CSA Certified |
It accepts 22‑16 AWG solid or stranded copper conductors, with diameters from about 0.5 mm up to 1.5 mm.
A 16 AWG wire can carry up to 10 amps through the connector.
The connector is UL Listed and CSA Certified, meeting UL 153 paragraph 14.2 and other applicable standards.