Heat Shrink Terminology

Heat Shrink Vocabulary

Here are some common terms you may encounter when browsing the products on BuyHeatShrink.com.

Dual Wall

Dual wall is a term to describe ANY heat shrink with an adhesive lining. Dual wall and adhesive lined mean the same thing. Sometimes those terms are used separately and sometimes together.

Dual wall adhesive lined heat shrink comes with a preapplied layer of hot melt adhesive on the inside of the tubing. This inner lining of hot melt glue adds a second barrier (or wall) against environmental contaminants like dust, dirt, water, and even air. These waterproof, hermetic seals provide a superior level of protection over general purpose heat shrink (which only has one wall–the tubing itself).

Shrink Ratio

All heat shrink tubing has a shrink ratio listed as: "original size:final size". These ratios are standardized across different brands and types of tubing.

The most common heat shrink ratios are:

  • 2:1
  • 3:1
  • 4:1
  • 6:1

Each shrink ratio indicates how much larger the original size of tubing is compared to its size after heating and shrinking. The higher the shrink ratio, the more your tubing will shrink. Choosing the right heat shrink ratio (and tubing diameter) is crucial for achieving perfect fits, precise coverage, and powerful seals. Expect to use about 75% of a shrink tube's listed shrink potential. The larger your connection or plug, the higher ratio you'll need. When in doubt, opt for a higher shrink ratio.

304 vs 316 Stainless Steel

Both 304 and 316 are designations of stainless steel cable ties. Stainless steel ties are truly the strongest, longest lasting, and highest performing cable ties on the market. If you need a cable tie that withstands the highest heat and worst chemicals without flinching or failing, stainless steel is for you.

The biggest difference between 304 and 316 is that 316 stainless steel is SALTWATER-PROOF!

Here's a chemical breakdown between the two different options:

304-

  • 8-10.5% nickel
  • 18-20% chromium

316-

  • 10-14% nickel
  • 16-18% chromium
  • 2-3% molybdenum–this is the magic ingredient that gives 316 a slight edge in power and performance and all its saltwater resistance. This makes it the ideal choice for use near salt water, pools, boats, marines, and more.

Monofilaments and Multifilaments

These words help describe cable construction and are important when you're working with wires and electrical installations.

Monofilaments-

'Mono' means one. Monofilaments are solid wires made from a single, continuous strand. They're less flexible than multifilaments but more durable, which makes them great for permanent wire applications like households and circuit boards thanks to their excellent grounding and stability.

Multifilaments-

Just like "multi" means many, these are made from multiple smaller strands that are usually twisted (or braided) together. Multifilaments are sometimes called "stranded wire". They're stronger and more flexible than monofilaments, which allows them to withstand extreme vibrations and perform reliably in motion and longer runs. You can find (or use) them in the electrical systems of vehicles, industrial machinery, and consumer electronics.

UL Ratings

UL or Underwriters Laboratories provides global, safety and quality guarantees to help consumers make informed decisions. In the heat shrink universe, UL ratings distinguish between fire safety standards and differing levels of protection. Since heat shrink tubing and electrical wiring are interconnected UL ratings can tell you more about a specific product or material's safety standards, flammability, voltage ratings, heat tolerance, flame retardancy, and usage specifications.

Here are some of the most common UL ratings you'll see on BuyHeatShrink.com:

  • 1441 VW
  • UL94V-0
  • UL94V-2
  • UL 244

For more information and to ensure a safer workplace, take the time to explore Underwriters Laboratories or try a free search for specific UL ratings.

Plenum

Plenum wiring, sleeving, and cable ties are specially designed to meet safety standards and product specifications for applications that will be in plenum spaces. Plenum spaces are for air handling and distribution in inhabited buildings. Materials have to meet specific UL and NEC codes to be rated for use in plenum spaces.

Secure your plenum spaces with the safest and best only from BuyHeatShrink.com

Refer to NEC (National Electrical Code) for more!

Limiting Oxygen Index

The LOI helps measure how easily something catches fire and keeps burning. Since the air we breathe is approximately 21% oxygen any material with an LOI less than that burns easily. Materials with higher LOIs burn slower and the best LOI ratings are self-extinguishing.

Any product with an LOI higher than 28% won't sustain combustion. So these products add no fuel to an existing fire and stop burning immediately when the ignition source is removed.

Products with the highest LOIs are the most resistant to burning and the safest

Here are some LOI Values for common plastics:

  • Polyethylene, Polypropylene: 17.4%
  • PET: 21-34%
  • Nylon 6.6: 24-29%
  • Nomex: 28%
  • Polyvinyl Chloride (PVC): 45-49%
  • Halar (E-CTFE): 64%
  • Teflon (PTFE): 95%

Visit BuyHeatShrink.com for all your heat shrink needs, products, and questions. We're always happy to help!


Heat Shrink Terminology

Heat Shrink Terminology