UL 3172 Silicone Fiberglass Wire — 200°C / 600V AC / 26–18 AWG
UL AWM Style 3172 is a single-conductor extruded silicone rubber insulated wire with a fibrous braid outer covering, rated at 200°C and 600V AC under UL Subject 758. The insulation uses extruded silicone rubber (30 mils min average / 27 mils min at any point) with one or more glass or aramid braid fibrous coverings meeting the SF-2 Fixture Wire specification. The permitted use is internal wiring of appliances.
UL 3172 differs from UL 3135 (bare silicone rubber, totally enclosed use) in that the fiberglass or aramid braid outer covering provides mechanical protection for the silicone insulation during installation and routing. For higher voltage DC applications, see UL 3239.
Technical Specifications — UL AWM Style 3172
| Parameter | Specification |
|---|---|
| UL AWM Style | 3172 |
| UL Subject | 758, Section 3 |
| Temperature Rating | 200°C maximum |
| Voltage Rating | 600V AC |
| AWG Range | 26 AWG – 18 AWG, solid or stranded |
| Insulation Material | Extruded silicone rubber (SR) |
| Insulation Thickness | 30 mils min average / 27 mils min at any point |
| Outer Covering | One or more glass or aramid braid fibrous coverings — SF-2 type |
| Conductor | Solid or stranded copper; bare or tinned |
| Flame Rating | Horizontal flame |
| UL Recognition | UL Recognized Component — file on record |
| Permitted Use | Internal wiring of appliances |
| RoHS / REACH | Documentation available on request |
Construction Note — UL 3172 vs UL 3135
Both UL 3135 and UL 3172 are rated 200°C / 600V AC with extruded silicone rubber insulation at 30 mils minimum average wall. The difference is the outer covering: UL 3135 has no braid covering and is restricted to use where totally enclosed; UL 3172 adds one or more glass or aramid braid fibrous coverings (SF-2), providing mechanical protection during installation and routing. Selection between the two depends on whether the routing path requires the mechanical protection of the braid and whether the totally enclosed condition of UL 3135 is met.
Typical Applications
- Internal wiring of appliances where the wire is routed near heating components within the appliance enclosure
- Internal lead connections in thermal appliance assemblies — oven internal wiring, heating appliance internal routing
- OEM appliance wiring harnesses requiring 200°C silicone insulation with fiberglass or aramid braid mechanical protection
- Internal wiring sections where the glass or aramid braid outer covering is required by the appliance design
Selection Notes
For general silicone wire for internal wiring where totally enclosed, UL 3135 (200°C / 600V, bare silicone, 26–12 AWG) may be applicable. For applications requiring temperatures above 200°C, mica tape and glass braid constructions such as UL 5107 are required. For fluoropolymer insulation, see UL 1332 (200°C FEP) or UL 10362 (250°C PFA).
Related UL Styles
- UL 3172 Silicone Fiberglass Wire — category page
- UL 3135 Silicone Wire — 200°C / 600V, bare silicone, totally enclosed
- UL 3239 High Voltage Silicone Wire — up to 60,000V DC
- UL 1332 FEP Wire — 200°C / 300V
- UL 5107 Mica Wire — 200°C or 450°C / 600V
- All AWM Wire Styles
Ordering Information
Specify AWG size, conductor type (bare / tinned copper), braid colour, packaging format, quantity, and destination. Response within 12 hours.



