What You Need To Know About The Materials Used To Make Seat Belts?

What You Need To Know About The Materials Used To Make Seat Belts?

What You Need To Know About The Materials Used To Make Seat Belts?

The material used for seat belts is among the essential things that repair shops for automotive consider when repairing a seat belt. One of the significant factors that make it so important is compatibility. The replacement and original components should have the same characteristics.

Additionally, the type of material that is used in the manufacturing process can affect repair costs. Below, we offer a complete description of manufacturers’ materials to create seat belts.

Strength and Durability Requirements

Seat belts require the highest tensile force to perform their job effectively. The recommended strength ranges from 3000-6000 lbs. Furthermore, seatbelts are required to support a 1500kg static load-bearing capacity. This ensures that the seat belts will help save lives.

In addition to the strength of the belt, durability is also crucial. Seat belts should be light, heat-resistant, abrasion-resistant, lightweight, and flexible. They should also provide excellent retraction. A good quality seat belt can last for ten years. Other durability and strength requirements include:

  • Resistance to common chemical
  • It isn’t easy to ignite.
  • As high as 25% lengthening at break
  • The melting point is 260degC.
  • Use the device with care in cold temperatures
  • A low regain of moisture, at 0.4 percent

Types of Materials Used

If you are looking for repair for your seat belt service, the best choice is to choose a seat belt made of top-quality materials. A crucial thing to consider is that the kind of material used will affect the price of repairs to your seat belt. Generally, two primary materials are used to manufacture seat belt processes: polyester and nylon. In the list of synthetic fibers, nylon is the most durable.

At present, nylon is rare among manufacturers of seat belts. It is because nylon is more susceptible to wear and tear, which isn’t ideal. In addition, abrasions or damage on the belt means it is unsuitable to wear as it lowers the tensile strength.

Nowadays, the most sought-after material is 100 percent polyester. Polyester is longer-lasting and has a more excellent resistance to wear and tear. Additionally, it has a more extraordinary tenacity of about 10g/den compared to nylon.


The seat belts we use in our cars, trucks and other vehicles are woven with polyester. This gives them a strength of 28 kNw or 6,000 pounds, enough to keep the person in place during an impact.

They are also woven with run-proof selvages to ensure they don’t break when they’re pulled apart at a specified rate. This is a critical design feature that keeps us safe.

Another key part of the seat belt is the retractor. This mechanism spools the webbing and lets it be withdrawn or pulled back into the retractor.

The retractors also secure the webbing in place when an accident occurs, so that it can restrain the passenger and protect them from injury. This is an important safety feature that could save lives.


The buckle is the piece of hardware holding the seat belt. Often, the buckle is made of stainless steel. It has a latch plate that inserts into a small slit and should audibly snap when you push it.

Buckles also feature a pretension that tightens the seat belt in a crash to prevent it from slackening too far or allowing impact with the steering wheel, windshield, instrument panel, or vehicle ejection. A faulty pre-tensioner can cause the seat belt to be slack and unfastened in an accident, resulting in severe injury or death.

Several problems have been associated with current buckle design and manufacturing. Two of these are false latching when a buckle seems fastened but isn’t, and inertial unlatching when a buckle latch fails in a crash, letting the seat belt unfastened.


Seat belts are made of several materials, including webbing, buckles, straps, and hardware. All of these parts have their own requirements regarding strength and durability.

Webbing in the pelvic restraint portion of a Type 2 seat belt assembly must withstand a tensile force of at least 22,241 N (5,000 pounds) without fracture. The upper torso portion of a Type 2 seat belt assembly shall withstand a tensile force of no less than 17,793 N (4,000 pounds) without fracture when tested by the procedure specified in S5.2(c)(2).

Attachment hardware must be free of ferrous corrosion on significant surfaces except for permissible corrosion at peripheral edges or holes on underfloor reinforcing plates and washers. As prescribed, the corrosion resistance test does not apply to attachment hardware made from corrosion-resistant steel containing at least 11.5 percent chromium or attached to an electrodeposited nickel, copper, and nickel coating in S4.3.

Cover Fabric

The cover fabric used for seat belts is durable and lightweight. Its high abrasion resistance and strength retention helps prevent injuries during accidents, and has good sliding efficiency to make the buckle easier to attach/detach.

The woven fibers used for seat belts have good strength (seatbelt yield strength is measured in tons) and stretch when under load to reduce the energy placed on the person during a car crash. This is important because when a person is accelerated, high-pressure zones occur in the body where objects fixed to the vehicle’s structure are placed.

Usually, polyester fiber is used for making seat belts. This fiber has an optimized intrinsic viscosity, tensile strength, and total fineness to provide good abrasion resistance, strength retention, and mechanical properties.

Fabric Specifications

Seat Belt 2

Manufacturers produce seat belts using a tight weave of filament yarns made of polyester or nylon filament yarn into webbed patterns. Typically, they weave seatbelts using the satin weave or a herringbone twill with eight shafts. In addition, thanks to technological advances manufacturing companies weave the yarn with a range of 3000 pieces per minute.

Advantages of Different Materials

A significant aspect of repair services for seat belts is deciding on a suitable material. Different materials offer different benefits. As mentioned, nylon is among the most synthetic solid fibers available.

It doesn’t rot rapidly and is exceptionally comfortable and smooth. Following weaving, the fabric doesn’t leave any rough edges of fiber. However, it is the most sought-after seatbelt fabric. Polyester is of a higher quality than nylon because of its greater rigidity. Also, it has less extensibility, making it suitable for seatbelts.

Regulations Surrounding Seat Belt Manufacturing

Manufacturers must take particular caution when creating seat belts. In particular, they need to ensure that the hem is resistant to abrasion and comfortable. Furthermore, they have to conduct standards and performance tests to ensure they produce belts of the best quality possible.

They need to test the mechanical properties of components like thickness, width, and elongation of wet or dry webbings, the strength of breaking, and the abrasion resistance.

Final words

The type of material used for a seat belt dramatically affects the repair cost. As mentioned above, nylon and polyester are the two primary materials manufacturers use to create seat belts. Polyester is currently the most frequently used material, with more rigidity and less stretch than nylon.