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White heat-shrink sleeves on a roll with black print

Brady Corporation

Brady PermaSleeve Heat-Shrink Sleeves M21-187-C-342 Black On White

SKU CH-46QX-HQFSA

Heat-shrink polyolefin sleeves with 3:1 ratio print on Brady printers for permanent wire identification and insulation from -55 °C to +135 °C

  • Permanent wire identification with fade-resistant B-342 polyolefin
  • 3:1 shrink ratio insulates and protects cables in extreme heat
  • Thermal-transfer and dot-matrix printable for clear, legible markings
  • Withstands -55 °C to +135 °C for harsh environments
  • Fire-retardant material meets demanding safety requirements

Wire-marking heat-shrink sleeves

Brady PermaSleeve M21-187-C-342 sleeves are non-adhesive polyolefin tubes that shrink 3:1 around wires or cables for permanent identification and insulation. They accept thermal-transfer or dot-matrix printing in black on white for clear, legible markings that resist fading in harsh environments.

Check printer and wire dimensions

Verify that your Brady printer supports thermal-transfer or dot-matrix output on B-342 material and that the sleeve inner diameter before shrinking fits the wire bundle you intend to mark. Confirm the 3:1 shrink ratio will fully cover the conductor after heating with an industrial-grade heat gun.

Stable in sustained temperature extremes

The irradiated polyolefin operates continuously from -55 °C to +135 °C and is fire-retardant, so markings remain legible and the sleeve retains its grip during prolonged exposure to temperature cycling, abrasion and chemical contact.

Highlights

  • Permanent wire identification with fade-resistant B-342 polyolefin
  • 3:1 shrink ratio insulates and protects cables in extreme heat
  • Thermal-transfer and dot-matrix printable for clear, legible markings
  • Withstands -55 °C to +135 °C for harsh environments
  • Fire-retardant material meets demanding safety requirements

Specifications

No published specifications for this item yet.

Questions about this item

What comes in the M21-187-C-342 pack and do I need a separate printer?

The pack contains heat-shrink sleeves made from B 342 polyolefin material. You need a Brady thermal-transfer or dot-matrix printer to print on them, plus an industrial-grade heat gun to shrink the sleeves onto wires.

How do I choose between the available B 342 colours for my wiring job?

B 342 sleeves come in white, yellow, black, red, orange, green, blue, violet, pink, grey and brown. Pick a colour that contrasts with your wire insulation and matches any site colour-coding standard you follow.

What does the 3:1 shrink ratio mean when the sleeve is on a real cable?

A 3:1 ratio means the tubing shrinks to one-third of its supplied diameter when heated, gripping the cable tightly for permanent identification and insulation from -55 °C to +135 °C.

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