Fenner Dunlop UsFlex® - Fenner Dunlop Conveyor Belting

Fenner Dunlop UsFlex®



Watch Usflex in action

Key features of Fenner Dunlop UsFlex

Unrivaled impact,
rip and tear resistance

Longitudinal rip resistance that is more than five times stronger than multi-ply belts.

load support

Excellent in mining, quarry, wood, paper and pulp, recycling, road construction, steel and transshipment industries.


The UsFlex carcass is based on the straight-warp principal.


In some applications, especially primary and secondary crushers, even the strongest and heaviest conventional belts can be ripped or torn by large lumps of heavy, sharp objects, either falling from a height or becoming trapped. Belts can often be destroyed within a matter of weeks or months. Our solution to this problem is UsFlex, which has longitudinal rip resistance more than five times that of multi-ply belts of equivalent rating because of our unique straight-warp construction. UsFlex provides impact resistance up to three times greater than that of conventional plied belting. This unequaled toughness means the belt will not be easily damaged in the loading and conveying of large, sharp material. As a result, UsFlex will provide the longest belt life in the harshest conditions!

Perfect for the following industries:

  • Cement
  • Mining
  • Power generation
  • Quarry
  • Recycling
  • Steel
  • Transshipment
  • Wood

Belt characteristics

UsFlex owes its outstanding impact and tear resistant characteristics to an innovative woven straight-warp carcass that is unique to Dunlop. This consists of heavy strands of polyester running lengthwise and heavy nylon strands running crosswise held in position by a strong yarn. The strands are completely straight in both directions and not interlocked as in a conventional belt carcass. This allows the weft to float free from the warp, thereby minimising the peak point of impact because the energy is absorbed over a larger area, providing maximum protection to the carcass.

Suitable for use in all areas, especially in high impact conditions and low maintenance environments including the mining, quarry, wood, paper and pulp, recycling, road construction, steel and transshipment industries.

Fenner Dunlop UsFlex is available from stock in two tensile strengths; 630/1 6+3 and 1000/2 8+3 in widths up to 2000mm. UsFlex belts are supplied with the abrasion resistant ‘RS’ cover as standard. The Fenner Dunlop RS cover grade exceeds the very highest DIN and ISO grades (DIN W and ISO 14890 ‘D ‘). Other tensile strengths and cover qualities can be made to or

The UsFlex carcass is based on the straight-warp principal and can be supplied in either single ply or two-ply versions.

Heavier and thicker belt is not a solution

Usflex provides amazing resistance against impact and puncture

Learn more!

Rip, Impact
& Tear testing


The ‘secret’ behind the amazing rip resistant characteristics of UsFlex is the use of a unique and innovative ‘straight-warp’ woven fabric ply. This consists of heavy strands of polyester running lengthwise and nylon running crosswise. The strands are completely straight in both directions and not interlocked as in a conventional belt carcass. This allows the weft to float free from the warp. This means that if a sharp object penetrates the carcass the nylon crosswise strands have the strength and ‘freedom’ to compact (gather) together, effectively forming an increasingly stronger barrier. It is a broadly similar principle to that of a fabric rip-stop breaker ply but significantly stronger and more effective.

Rip resistance in newtons
(for type 1000 n/mm)



Compared to conventional multi-ply and solid woven belting, the impact resistance of UsFlex is proven to be significantly superior. This is because the unique UsFlex design minimises the peak point of impact and absorbs (dissipates) the energy over a larger area compared to a conventional high tensile EP or EPP belt. For example, a single-ply UsFlex type 630/1 has the impact absorbing qualities of a 4-ply EP belt type 1600/4 or an EPP 1250/2. The chart shows the results of impact tests on 630 rated UsFlex, Solid woven and multiply belting.

Impact energy to
maximum load

Impact chart


The tear resistance of UsFlex, measured according to the international EN ISO 505 standard, also significantly exceeds that of conventional multi-ply belts with comparable tensile strength. Tests for rip and tear resistance are only made on the actual belt carcass so the top and bottom covers are always removed. This ensures that the thickness and quality of the cover do not influence the accuracy and consistency of the tests.


What they say about the product

"We used to replace our belts every three to six months before we started fitting UsFlex belts. Now it can be four or five years before we need to fit a replacement. UsFlex really is an amazing belt"

Quarry Manager. Scotland.


Finger splice

For belts operating in demanding conditions having the strongest possible splice joints while still retaining the maximum amount of tensile strength is even more important than usual. A conventional step splice or fastener will always create a proportional loss of tensile strength. At Dunlop, we recommend the finger splice method that creates the strongest and most reliable joint possible (up to 90% of the belt’s original tensile strength).
Finger splice

Difficult Environments

cover grades available for Fenner Dunlop UsFlex®

To provide optimum carcass protection, Fenner Dunlop RAS covers are fitted as standard because of its excellent resistance to cutting combined with outstanding resistance to abrasion. Fenner Dunlop RS signifi cantly exceeds the highest abrasion standards for both DIN W and the equivalent ISO 'D'standard. Other qualities, such as oil, fi re and heat resistant covers are available. All Fenner Dunlop cover qualities are anti-static according to EN ISO 284 and are extensively ozone tested in compliance with EN ISO 1431 ozone resistance (50 pphm, strain 20%, 96 hours no cracking) and resistance to the damaging effects of ultra-violet in order to avoid premature failure due to cracking of the belt surface.

  • Abrasion resistance
  • Anti-static
  • Fire resistance
  • Heat resistance
  • Oil resistance
  • Ozone & UV resistance
  • Rip & Impact resistance

When you buy Fenner Dunlop
you also buy peace of mind

Read more about our products

Fenner Dunlop Conveyor Belting
Dunlop Conveyor Belting
The Longest Lasting Conveyor Belts

We use cookies to optimise the website, show targeted advertisements and collect statistics. By using our website you automatically agree to the use of cookies. You may change the settings on the Privacy Settings page at the bottom of the website at any time.

Privacy Settings saved!
Privacy Settings

When you visit any web site, it may store or retrieve information on your browser, mostly in the form of cookies. Control your personal Cookie Services here.

These cookies may be set by our advertising partners such as Google through our website. They may be used by us to build a profile of your interests and display relevant ads on other sites. They do not store personal information directly, but rely on unique identification of your browser and Internet equipment. If you do not allow these cookies to be used, you will experience less targeted advertising.

ad_storage — Enables storage, such as cookies (web) or device identifiers (apps), related to advertising.
ad_user_data — Sets consent for sending user data to Google for advertising purposes.
ad_personalization — Sets consent for personalized advertising.
analytics_storage — Enables storage, such as cookies (web) or app identifiers (apps), related to analytics, e.g. visit duration.
wait_for_update — Sets a time in milliseconds to wait for a consent update call.

Decline all Services
Accept all Services