Power Systems Grade PermaSleeve Marker

B-312 is a white, thermal transfer printable irradiated polyolefin heat shrink sleeve with a 3:1 shrink ratio, listed by Brady for wire identification and insulation purposes. It fits only wires inside the four published diameter ranges (1/8" through 3/8" markers, spanning 0.046 - 0.320 in / 1.17 - 8.13 mm across all sizes combined), and it has to be recovered with an industrial grade heat gun at a recommended minimum recovery temperature of 155°C (311°F). Brady's own note on the sheet states that all values shown are averages and "should not be used for specification purposes," so anything contract- or safety-critical has to be confirmed with Brady.

Orderable Part Numbers, Packaging & Distributor SKUs

Official Brady SKUs, roll dimensions, package quantities, list pricing, Grainger part numbers, and printer compatibility for B-312.

Extracted directly from Brady Technical Data Sheets to prevent real-world application failures and chemical degradation:

• UL approval, quoted in full: "B-312 is a UL Recognized Component to UL224 Extruded Insulated Tubing. See UL file E333786 for specific details." The sheet gives no further UL detail and defers to that file.
• WEEE-RoHS: the sheet does not state a compliance status. It only points to regional URLs: In Canada www.bradycanada.ca/weee-rohs, In Europe www.bradyeurope.com/rohs, In Japan www.brady.co.jp/products/labelsuse/rohs, All other regions www.bradyid.com/weee-rohs.
• The low end of the operating temperature range is not internally consistent on the sheet. The text layer reads "-30°C (-67°F) to +125°C (+257°F)", but -30°C converts to -22°F and -67°F converts to -55°C, so the two printed low-end figures do not describe the same temperature. The high end (+125°C / +257°F) does convert correctly. Confirm the low-temperature limit with Brady before relying on it.
• Minus signs are encoded in this PDF as soft hyphens that do not render, so several values display on screen without their negative sign: the operating range appears as "30°C (67°F) to +125°C (+257°F)", the low service temperature row appears as "1000 hours at 94°F (70°C)", and the shelf life storage range appears as "32-95 degrees °F (035 degrees °C)". The negative reading is the correct one for the latter two, since -70°C equals -94°F exactly and 0-35°C equals 32-95°F exactly.
• The Solvent Resistance row names a different material in its test method cell: "B342 white printed with R4300 and R6600, tested after unrestricted shrink at 200°C for 3 minutes". Every other product reference on the sheet reads "B-312". This sentence sits inside the TEST METHODS column of the Solvent Resistance row, so it describes the sample used for that row's "No visible effect" result. Whether "B342" is a typo for B-312 or a genuinely different material is not resolvable from this sheet.
• Ribbon choice changes the durability result, and the two ribbons must not be treated as interchangeable. In the chemical resistance testing the R4300-printed samples returned severe print fade with print illegible for JP-8 Jet Fuel, Gasoline and BIOACT EC-7R Terpene Cleaner after swab rub, while the R6600-printed samples returned no visible effect or slight print fade for those same reagents. Print adherence differs the same way (R4300: slight print fade; R6600: no visible effect).
• Shelf life is conditional on storage: it holds only "as long as this product is stored in its original packaging in an environment at 32-95 degrees °F (0-35 degrees °C) per SAE AS23053/5."
• The sheet places responsibility for fitness on the user: "It remains the responsibility of the user to assess the risk of using this product. We encourage customers to develop testing protocols that will qualify a product's fitness for use in their actual applications."
• Sheet-wide note: "All values shown are averages and should not be used for specification purposes." Brady further states that test data "shall not be relied upon by Brady customers for designs and specifications, or be relied on as meeting specified performance criteria," and directs customers developing specifications to contact Brady.
• Compliance data is second-hand: "Product compliance information is based upon information provided by suppliers of the raw materials used by Brady to manufacture this product or based on results of testing using recognized analytical methods performed by a third party, independent laboratory." Brady makes no independent representations or warranties on it and assumes no liability.
• The warranty section states buyers are expected to test the product in actual use and determine adaptability to their intended uses themselves; Brady's obligation is limited to replacement of product shown to be defective, and the warranty excludes any implied warranty of merchantability or fitness for a particular purpose.
• No footnote markers appear anywhere on this sheet.

ASTM Physical & Mechanical Properties

Standardized laboratory test data measured in accordance with ASTM D 1000, ASTM D 2979, and ASTM D 2671.

Thermal Transfer Ribbon Compatibility

Official Brady recommended ribbons engineered for maximum contrast, smear resistance, and UL certification compliance.

Chemical & Solvent Resistance Matrix

Standardized dip and rub immersion test observations across industrial fuels, oils, solvents, and cleaners.

Environmental & Aging Durability Testing

Verified Target Applications & Use Cases

• Wire identification and insulation purposes