Plastic buckles- what are they made out of?

Are all plastic buckles the same? No they are not.

There are three main plastics that buckles and other hardware for webbing are manufactured from:
1. Acetal
2. Nylon
3. Polypropylene

All have their strengths and weaknesses and many products are available in more than one plastic so you can choose what will work best in your application. Strength, resistance to heat or ultra-violet light and cost all factor in to what is best. So in alphabetical order lets dive in.

Acetal

Advantages:

  • Excellent resistance to immersion in water
  • Excellent resistance to chemicals and solvents
  • Fatigue resistant
  • Retains mechanical properties up to 250° F.

Disadvantages:

  • Poor resistance to acids
  • Subject to UV degradation

Nylon

Advantages:

  • Fatigue resistance
  • Good chemical resistance to oils and greases
  • Abrasion resistant
  • Tough and impact resistant
  • Heat stabilized versions are available which meet various NFPA standards (special order with minimum quantities)

Disadvantages:

  • High moisture pick-up with related dimensional instability
  • Attacked by oxidizing agents
  • Attacked by strong acids

Polypropylene

Advantages:

  • Excellent moisture resistance
  • Good impact strength

Disadvantages:

  • Degraded by UV
  • Attacked by chlorinated solvents and aromatics
  • Flammable

Putting the factors together Acetal provides the best performance of the three materials (other than for very specialized high temperature applications). So why do some vendors offer polypropylene buckles and hardware? Price. Polypropylene is around 15% less expensive and if price is the driving factor, it can’t be beat. You are trading off durability but in some applications that is not needed.

When you browse our selection of buckles and hardware we tell you what each piece is made from. That applies not only to plastic but also to metal products. In the case of stainless steel, we try to identify the class of material the piece is made out of so you can tell if it is type 316 which will not even stain or type 304 where you will see some rust stains over time.

If you have any questions give us a call, (253) 883-5800 and we will try to answer your questions.