Brady B-437: Thermal Transfer Printable Label Stock

B-437 is a matte topcoated polyvinylfluoride label stock with a permanent acrylic adhesive, printed by thermal transfer, and Brady lists it for cable and wire bundle applications and for label applications where self-extinguishing properties are required. Brady states it has been judged to be self-extinguishing by laboratory testing and that it meets the requirements of MIL-M-87958. Two limits to give a customer up front: Brady states that all values shown are averages and should not be used for specification purposes, so the customer has to qualify the product for their own application; and the three-year shelf life holds only while the product stays in its original packaging in an environment below 80° F (27° C) and 60% RH.

Orderable Part Numbers, Packaging & Distributor SKUs

Official Brady SKUs, roll dimensions, package quantities, list pricing, Grainger part numbers, and printer compatibility for B-437.

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

• Regulatory approvals: the sheet does not state a compliance status. It says only, "For information on the Weee-RoHS compliance status for a Brady Product go to one of the following websites:" and lists — 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
• Standards conformance (SPECIAL FEATURES): "B-437 meets the requirements of MIL-M-87958, Pressure Sensitive Adhesive Wire or Cable Marker and Identification specification."
• Self-extinguishing claim is qualified (SPECIAL FEATURES): "B-437 has been judged to be self-extinguishing by laboratory testing, and exhibits good solvent and heat resistance." The sheet attributes this to laboratory testing and names no agency listing or approval for it.
• Asterisk footnote below the 24 HOUR IMMERSION table, transcribed verbatim: "*Yellow and green labels had moderate to severe fade or discoloration in this solvent, all other labels had no visible effect unless mentioned. Overall the green topcoat had slight to severe discoloration in the following chemicals: Methyl Ethyl Ketone, 1,1,1-Trichloroethane, Methyl Alcohol, Gasoline, Mineral Spirits, SAE 20 Wt Oil, Skydrol® 500B- 4 and 10% NaOH."
• Scope of that footnote: the asterisk marker appears on exactly three cells, all in the EFFECT TO LABEL STOCK column of the 24 HOUR IMMERSION table — Methyl Ethyl Ketone, 1,1,1-Trichloroethane, and SAE 20 WT Oil at 70ºC. Its first sentence ("in this solvent") therefore reads as attaching to those three rows. Its second sentence ("Overall the green topcoat...") names a longer chemical list that includes reagents carrying no asterisk (Methyl Alcohol, Gasoline, Mineral Spirits, Skydrol® 500B-4, 10% NaOH), so that sentence's scope is broader than the marked cells and is not confined to any one row. Quoted above so a reader can judge it.
• Ribbon scope in the chemical resistance tables is ambiguous: the preamble states "Samples printed with Series R4300 and R6200 ribbons and laminated to aluminum panels...", but each table carries only one ribbon result column, headed "R4300". No R6200 column is printed in either the 15 MINUTE IMMERSION or the 24 HOUR IMMERSION table. Do not read the R4300 column as an R6200 result.
• Ribbon scope in the performance properties table is likewise ambiguous. The preamble reads: "Performance properties tested on B-437 printed with Series R4300 using the BradyPrinter™ THT Model 300X thermal transfer printer. Printed samples were laminated to aluminum and allowed to dwell 24 hours before exposure to the indicated environments. Unless noted, results are the same for both ribbons." Only R4300 is named in that sentence; the second ribbon is not identified there. R6200 appears elsewhere on the sheet (the Abrasion Resistance row and the chemical resistance preamble), while RECOMMENDED RIBBONS lists Brady Series R4300 only.
• Abrasion Resistance is reported per ribbon and the two verdicts differ — "R4300: Moderate print removal and print smear. Print still legible" and "R6200: Slight print removal. Print still legible". Neither verdict carries over to the other ribbon.
• High Service Temperature results extend past the stated test condition. The TEST METHOD cell states only "30 days at 275°F (135°C)", but the result cell reports outcomes at both 135ºC and 145ºC, including "At 145ºC slight color fade all colors except yellow, which had severe color fade" and "Slight shrinkage at 145ºC". The sheet gives no test-method row for the 145ºC condition.
• Storage condition attached to shelf life: "Shelf life is three years from the date of receipt for this product as long as this product is stored in its original packaging in an environment below 80° F (27° C) and 60% RH."
• User responsibility for fitness for use, stated immediately after the shelf life sentence: "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."
• Data may not be used for specification purposes: "Note: All values shown are averages and should not be used for specification purposes." The sheet continues: "Test data and test results contained in this document are for general information only and shall not be relied upon by Brady customers for designs and specifications, or be relied on as meeting specified performance criteria. Customers desiring to develop specifications or performance criteria for specific product applications should contact Brady for further information."
• Compliance data disclaimer: the sheet states that product compliance information comes from raw-material suppliers or from third-party independent laboratory testing, and that Brady makes no independent representations or warranties, express or implied, and assumes no liability in connection with the use of that information.
• Warranty limitation: the sheet states products are sold on the understanding that buyers will test them in actual use and determine adaptability to their intended uses; the warranty covers defects in material and workmanship, is limited to replacement, does not extend to persons obtaining the product from the buyer, and excludes any implied warranty of merchantability or fitness for a particular purpose and any liability for consequential damages.

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

• Cable and wire bundle applications and label applications where self-extinguishing properties are required