Reinforcement Options for Timing Belts

Timing belts have a series of evenly spaced teeth on the inside circumference, making use of positive engagement between two sets of meshing teeth in order to prevent slippage and minimize relative motion between the elements in mesh. However, most timing belts rely on some sort of reinforcement to add strength to the belt. Four of the most common materials are steel, Kevlar, polyester, and fiberglass. 


Steel has an impressive tensile strength of 360,000 lbs/, as well as a low elongation rate. This makes steel an excellent option for rapid start/stop operations. Because of its excellent dimensional stability, steel is also a good choice for extreme temperature environments, both high and low. However, it should be noted that steel has low vibration absorption capabilities.


Kevlar reinforced belts offer positive, nonslip, accurate power transmission without any unwanted vibration, chatter, or backlash. They have impressive shock resistance capacities and a very high load capacity. Kevlar boasts a tensile strength of 400,000 lbs/, and also has a fairly low elongation, making Kevlar reinforced belts durable and flexible. Kevlar is an excellent option for applications that involve high intermittent shock loading.


When compared to Kevlar and Steel, polyester does not have as high of a tensile strength. The tensile of polyester is roughly 160,000 lbs/, less than half of that of Kevlar. However, the major advantage of polyester is its low modulus of approximately 2,000,000 lbs/ This means that polyester reinforced timing belts rotate more smoothly, making polyester reinforcement an ideal option for timing belts in applications such as small diameter pulleys or any kind of high-speed application. Polyester is also quite elastic, meaning it has excellent shock absorption capabilities and can minimize unwanted vibration. 


Fiberglass has a tensile strength comparable to that of steel, at 350,000 lbs/in2. It is high-strength, low-stretch, and boasts a 100 percent elongation recovery. It also has excellent dimensional stability and an excellent chemical resistance, which make it a good option for corrosive environments.

Timing Belt Reinforcement with Beltcorp

Belt Corporation of America has years of experience providing reinforcement options for industrial belts across a variety of different industries. Contact us today to learn how we can provide you with the exact materials that you need for your application.