UL 5107 8 AWG Mica Wire — 30/15 Mil Construction
UL AWM Style 5107 is a single or multiple conductor with other-than-extruded insulation, rated 200 or 450°C and 600 Vac with a Horizontal flame classification. At 8 AWG, the Style requires a minimum average thickness of 30 mils for the total mica tape layers and 15 mils for the treated glass braid. 8 AWG is also the largest conductor size in the Style that may be either solid or stranded; every size above it must be stranded.
This page covers that 8 AWG construction: where it sits in the Style’s size groups, what the 30/15 mil minimum averages mean, how the conductor-form boundary works, and what the Use permits. For the broader Style overview, see the UL 5107 Mica Wire category.
Verified UL 5107 8 AWG Technical Specifications
| Parameter | UL AWM Style 5107 record, applied to 8 AWG |
|---|---|
| Style | 5107 |
| Description | Single or Multiple conductor with other-than-extruded insulation |
| Conductor size | 8 AWG (within the 26 AWG – 550 kcmil Style range) |
| Conductor form | Solid or stranded (permitted for 26 – 8 AWG) |
| Temperature | 200 or 450°C |
| Voltage | 600 Vac |
| Flame | Horizontal flame |
| Insulation | Mica tape with braid, or Mica composite (see Facing Page) with braid |
| Mica thickness (11–4 AWG group) | 30 mils (0.76 mm) minimum average thickness of total mica tape layers |
| Braid thickness (11–4 AWG group) | 15 mils (0.38 mm) minimum average thickness of treated glass braid |
| Braid treatment | Silicone Varnish or TFE Finish |
| Marking | General |
| Use | Internal Wiring of high-temperature equipment where not subjected to repeated flexing and protected from mechanical abuse, and where the acceptability, including current-carrying capacity, has been determined by Underwriters Laboratories Inc. |
Four points in this table need clarification. First, the millimetre values are arithmetic conversions (1 mil = 0.0254 mm), not separate UL specifications. Second, both thickness values are minimum averages; the record states no minimum-at-any-point value. Third, the record does not tie either temperature rating to a braid treatment or mica material. Fourth, the record does not state a conductor material or plating; these are confirmed according to the qualified ordered construction.
8 AWG — The Solid-or-Stranded Boundary in Style 5107
The conductor field of Style 5107 reads: “26 AWG – 550 kcmil. Solid or stranded for sizes 26 – 8 AWG; Stranded only for larger sizes than 8 AWG.” That sentence divides the range in two:
- 26 AWG through 8 AWG: solid or stranded conductors are both permitted.
- Sizes larger than 8 AWG: stranded conductors only.
8 AWG is the last size in the first band. It is therefore the largest Style 5107 size that may be ordered with a solid conductor. The next size in the Style’s thickness schedule after 8 AWG within the 11–4 AWG group, and every size up to 550 kcmil, must be stranded.
The record states only which forms are permitted. It does not rank solid against stranded, and this page does not attribute any mechanical, handling or flexibility advantage to either form. Which form applies to an 8 AWG order is a construction choice to state in the RFQ. If a stranded conductor is chosen, the stranding detail is confirmed for the ordered construction, since the record does not define strand count, strand diameter or lay.
30 Mil Minimum-Average Mica Tape Layers
Style 5107 sets insulation thickness by conductor-size group. 8 AWG falls in the 11–4 AWG group, so the applicable mica requirement is a minimum average thickness of 30 mils (0.76 mm by unit conversion) for the total mica tape layers.
- “Total mica tape layers”: the requirement applies to the combined thickness of all mica tape layers, not to a single tape.
- “Minimum average”: the average thickness of those combined layers must not fall below 30 mils.
The 25-mil value of the 26–12 AWG group does not apply to 8 AWG. The 30-mil figure is not a nominal, exact or typical thickness, and it is not a minimum at any point; the record states no point minimum. The actual mica thickness in an ordered construction may exceed 30 mils. The record also does not specify the number of tape layers, tape width or overlap.
15 Mil Minimum-Average Treated Glass Braid
For the same 11–4 AWG group, the Style requires a minimum average glass braid thickness of 15 mils (0.38 mm by unit conversion). The 7-mil value of the 26–12 AWG group does not apply to 8 AWG. As with the mica layers, 15 mils is a minimum average only; it is not nominal or exact, and no minimum-at-any-point value is stated.
The record describes the braid as “Glass Braid Treated with Silicone Varnish or TFE Finish.” Either treatment is permitted by that wording. The record does not state that one treatment corresponds to 200°C and the other to 450°C, and this page does not create that link. Which treatment applies to an order is confirmed against the qualified construction for the ordered temperature rating. The record also defines no yarn size, braid angle or coverage and attributes no performance to the braid or its treatment.
Mica Tape with Braid or Mica Composite with Braid
The Style’s insulation entry reads: “Mica tape with braid, or Mica composite (see Facing Page) with braid.” Two insulation systems are permitted, and both include a braid. The Style description is “other-than-extruded insulation”; it is not described in the record as a mineral-insulated metal-sheathed cable, a magnesium-oxide insulated wire or a ceramic cable, and none of those terms is used here.
The “Facing Page” referenced for the mica composite is not part of the data used for this page, so the composite’s makeup is not described. The record also does not identify mica type, grade, source or composition. Where a drawing specifies mica tape or a particular qualified mica composite, that requirement is stated in the RFQ and confirmed against the qualified construction.
200°C or 450°C / 600 Vac / Horizontal Flame
The rating field reads “200 or 450 deg C, 600 Vac, Horizontal flame.” The Style carries two alternative temperature ratings; a given construction is qualified at one of them, and the rating for an order is confirmed for the qualified ordered construction. The record does not describe either rating as continuous or long-term, and no selection rule, service life or thermal margin is derived from them here.
600 Vac is the only voltage rating in the record. No DC value or combined AC/DC figure applies. Horizontal flame is the flame classification; it is not VW-1, FT1 or FT2, and no vertical flame rating forms part of the Style. The 30/15 mil requirement for 8 AWG is the same at either temperature rating.
Internal Wiring Use and Installation Boundaries
The full Use wording is: “Internal Wiring of high-temperature equipment where not subjected to repeated flexing and protected from mechanical abuse, and where the acceptability, including current-carrying capacity, has been determined by Underwriters Laboratories Inc.” For an 8 AWG construction this means:
- Internal wiring of high-temperature equipment is the application. The Use does not name particular equipment types, and none is named here.
- No repeated flexing: the wire is not a flexible, moving, hinge, robotic or drag-chain cable. The record gives no bend radius or flex-cycle rating, and none is offered.
- Protected from mechanical abuse: exposed, open, outdoor, field, building, tray and direct-burial routing fall outside the Use.
- Acceptability, including current-carrying capacity, determined by UL: current capacity is not a Style-level figure. No ampacity is derived from 8 AWG, and general wiring-code ampacity tables are not applied to this AWM Style here.
How 8 AWG Fits the UL 5107 Size Groups
| Conductor size group | Total mica tape layers, min average | Treated glass braid, min average | Conductor form |
|---|---|---|---|
| 26 – 12 AWG | 25 mils | 7 mils | Solid or stranded |
| 11 – 4 AWG (includes 8 AWG) | 30 mils | 15 mils | Solid or stranded for 11 – 8 AWG; stranded only for 7 – 4 AWG |
| 3 – 4/0 AWG | 35 mils | 20 mils | Stranded only |
| 250 – 550 kcmil | 40 mils | 20 mils | Stranded only |
Two points in this table need clarification. First, the conductor-form column applies the record’s single rule (“solid or stranded for 26 – 8 AWG; stranded only for larger sizes than 8 AWG”) to each group, so the 11–4 AWG group straddles the boundary, with 8 AWG as its last solid-permitted size. Second, all thickness values are minimum averages, and each group’s values apply only to that group.
The Style also allows, as independent options, two or more insulated conductors cabled together with a maximum assembly O.D. of 1.500 inches, with a mica glass binder and/or fiberglass fillers; a shield of 36–30 AWG strands; and a treated glass braid over the assembly. These options are covered on the dedicated UL 5107 multi-conductor product page.
What Style 5107 Does and Does Not Define
For 8 AWG, the Style record defines the rating (200 or 450°C, 600 Vac, Horizontal flame); the permitted conductor forms (solid or stranded); the insulation systems (mica tape with braid, or mica composite with braid); the 30-mil minimum average of total mica tape layers; the 15-mil minimum average of treated glass braid; the braid treatment options; the marking field (General); and the Use with its conditions.
The Style record does not define:
- conductor material, plating or strand construction
- conductor resistance, conductor diameter or current rating
- minimum-at-any-point thicknesses
- finished outside diameter or tolerance
- mica type or the composition of the mica composite
- which braid treatment applies to which temperature rating
- bend radius, flex life or service life
Common Procurement Errors
- Applying the 25/7 mil values of 26–12 AWG to 8 AWG.
- Treating 30 or 15 mils as nominal, exact or point minimums.
- Ordering a solid conductor above 8 AWG.
- Leaving solid or stranded unspecified for 8 AWG.
- Assuming 200°C means silicone varnish and 450°C means TFE finish.
- Assuming a conductor material or plating.
- Deriving a current rating from 8 AWG.
- Specifying the wire for repeated flexing or unprotected routing.
- Assuming VW-1, FT1 or another vertical flame rating.
How to Specify UL 5107 8 AWG Mica Wire in an RFQ
The Style fixes the rating options, the permitted conductor forms at 8 AWG, the insulation systems, the 30/15 mil minimum averages, the treatment options and the Use. The following should be stated by the buyer and confirmed for the ordered qualified construction, not filled with assumed values:
- 8 AWG
- solid or stranded
- conductor material and finish requirement
- detailed stranding, if stranded
- required qualified temperature rating: 200°C or 450°C
- braid treatment requirement, if controlled
- mica tape or qualified mica composite requirement, if specified
- finished OD or dimensional tolerance, if controlled
- marking requirement
- quantity
- packaging
- documentation requirements
- equipment type
- routing location
- mechanical-protection conditions
- confirmation that repeated flexing is not involved
UL Marking and Documentation
Style 5107 wire is supplied as UL-recognized component wire where supplied under qualified manufacturing scope. The marking field of the Style record reads “General” and does not prescribe a fixed print legend. UL marking is applied according to the confirmed ordered construction, including its temperature rating, and should be confirmed at the order stage.
Applicable RoHS / REACH documentation can be confirmed according to the ordered construction. CE, UKCA, CSA, FT1, VW-1, CPR, VDE, DIN, EN and IEC are not declared for this product.
Commercial, origin, compliance and transport documents are identified during quotation and confirmed according to the order.
