Understanding Rubber Sliders in AS 4586 & AS 4663 Slip Testing

TLDR: Wet pendulum slip testing under AS 4586 and AS 4663 uses two rubber sliders: Slider 96 (Four S rubber) for most pedestrian surfaces, and Slider 55 (TRL rubber) for clay and concrete pavers, highly profiled surfaces, and wet barefoot areas. The sliders differ in rubber hardness and behaviour, and selection affects the test result and how it is classified. For NATA-accredited slip testing anywhere in Australia, call Australian Slip Testing on 0405 042 814.

If you have reviewed a wet pendulum slip test report, you will have seen a reference to either Slider 55 or Slider 96. These are the two rubber sliders recognised under AS 4586 and AS 4663 for use in wet pendulum testing, and understanding the difference between them matters when interpreting test results and assessing whether the right test was conducted for your environment.

Slider selection is a technical decision that directly affects the result. The same surface tested with Slider 55 and Slider 96 will produce different Slip Resistance Values, because the two rubbers interact with the floor differently. The SRV thresholds used for classification also differ between the two sliders, so results from one cannot be compared against the thresholds of the other.

What Are the Two Sliders?

During wet pendulum testing, a rubber slider is fitted to the pendulum arm and pressed against the wetted floor surface as the arm swings through its arc. The friction generated between the slider and the surface produces the Slip Resistance Value (SRV). The physical properties of the rubber determine how it responds to the surface texture, which is why slider choice matters.

AS 4586 and AS 4663 recognise two rubber sliders for this purpose: Slider 96, also known as Four S rubber, and Slider 55, also known as TRL rubber. They differ in hardness and in how they were formulated to behave under test conditions.

Slider 96 (Four S Rubber)

Slider 96 is the standard slider used for most pedestrian surfaces. It was formulated with deliberately poor abrasion resistance so that fresh rubber surfaces are produced during testing, reducing the risk of contamination building up on the slider and skewing results. It was also formulated to be temperature independent, meaning its behaviour does not change significantly across the range of temperatures encountered in normal testing conditions.

Under AS 4586, Slider 96 is used for general pedestrian areas including commercial flooring, external walkways, stairways, entry areas, and most surfaces in environments where pedestrians are wearing footwear.

Results using Slider 96 are classified into P ratings with the following SRV thresholds: P0 below 12, P1 from 12 to 24, P2 from 25 to 34, P3 from 35 to 44, P4 from 45 to 54, and P5 above 54.

Slider 55 (TRL Rubber)

Slider 55 is a softer, more resilient rubber. AS 4586 specifies its use for clay and concrete pavers, which have traditionally been tested with Slider 55, and for highly profiled surfaces where it generally produces more consistent results than Slider 96. When assessing products for wet barefoot areas, or unusually rough surfaces, Slider 55 is the preferred option under the standard.

The softer, more resilient nature of Slider 55 means it conforms differently to surface texture than Slider 96. On highly profiled or rough surfaces this tends to produce more consistent readings. On smoother surfaces the difference between the two sliders may be less pronounced.

Results using Slider 55 are also classified into P ratings, but the SRV thresholds differ from Slider 96: P1 below 20, P2 from 20 to 34, P3 from 35 to 39, P4 from 40 to 44, and P5 above 44. A Slider 55 result cannot be meaningfully compared against a Slider 96 threshold, or vice versa.

For a full explanation of P ratings and how they apply across different environments, see our guide to Australian slip resistance ratings.

How Slider Selection Is Determined

The appropriate slider is determined by the surface type and the environment, following the guidance in AS 4586. For most commercial and public pedestrian surfaces, Slider 96 applies. For clay and concrete pavers, highly profiled surfaces, and wet barefoot areas, Slider 55 is the correct choice.

In some environments, testing with both sliders provides a more complete picture of risk. A hotel pool surround accessed by both barefoot swimmers and shod staff is one example. An aquatic centre change room with a profiled tile surface is another. In these cases, the test report will include results for both sliders against their respective classification thresholds.

See our guide to wet pendulum slip testing for more on how the test is conducted.

AS 4586 and AS 4663

Both sliders are recognised under AS 4586, which covers slip resistance classification of new pedestrian surface materials, and AS 4663, which covers measurement of existing installed surfaces. Because both standards use the same rubber sliders and classification thresholds, results from new product testing and onsite testing of installed surfaces can be compared directly, and slip resistance can be tracked across the life of a surface.

A test report should always specify which slider was used. Without that information, the P rating cannot be correctly interpreted or compared against the appropriate classification thresholds.

Book NATA-Accredited Slip Testing

Australian Slip Testing conducts wet pendulum testing using both Slider 55 and Slider 96 in accordance with AS 4586 and AS 4663. Slider selection is determined based on the surface type and environment at each test location. Testing is available across Australia including Brisbane, Sydney, Melbourne, Adelaide, Perth, Darwin, Hobart, and Canberra.

Call 0405 042 814 or email info@australiansliptesting.com.au to book or discuss your requirements.