What is a Brady B-Number? The Complete Material Engineering Guide

Understanding the distinction between Brady Part Numbers (SKUs) and Material B-Numbers, face stock formulations, adhesive chemistries, and ribbon compatibility.

Figure 1: Exploded view — Release Liner, Cross-Linking Acrylic Adhesive, Film Facestock (B-Number), and Thermal Resin Print.ASTM D1000 & UL 969 Standard

1. The Fundamental Difference: Part Number (SKU) vs. B-Number

In industrial labeling and wire identification, one of the most common points of confusion is the difference between a Brady Part Number (SKU) and a Brady B-Number:

2. Major Brady Material Families Explained

• Self-Laminating Vinyl (e.g. B-427, B-417): Features a white printable area and a clear translucent tail that wraps around curved wires to protect the printed legend against oils, abrasion, and moisture.
• Heat Shrink Polyolefin (e.g. B-342 PermaSleeve, B-7642): 3:1 or 2:1 shrink ratio tubing meeting military (SAE AS23053/5) and aerospace flame resistance specifications.
• All-Weather Vinyl (e.g. B-595, B-581): Highly conformable 8-10 year outdoor film designed for pipe marking, chemical tanks, and facility signage.
• Polyester (e.g. B-423, B-483A, B-428): Dimensionally stable rigid film with exceptional chemical and abrasion resistance for rating plates and equipment asset tagging.
• Extreme High-Temperature Polyimide (e.g. B-652, B-724): Capable of withstanding 260°C–300°C wave solder and SMT reflow environments.
• Cryogenic Polyester (e.g. B-492 FreezerBondz): Formulated to adhere to already-frozen vials and withstand liquid nitrogen (-196°C).

3. What Do B-Number Suffixes Mean?

You will frequently encounter letters attached to B-numbers, such as B-499A vs B-499 or B-423Y vs B-423:

• "A" Suffix (e.g. B-499A, B-483A): Indicates an updated global manufacturing formulation or adhesive enhancement replacing legacy regional variants while retaining identical UL/CSA approvals.
• "Y" Suffix (e.g. B-423Y): Indicates a yellow face stock variant of the base material.
• "B" Suffix (e.g. B-361B): Indicates laser-printable sheet formulation optimized for desktop office printers.