Slip Resistance Information for Customers

James, formerly ASTM F 489-96

A test specimen (3” x 3”) is cut from forepart of the outsole and is secured to the bottom of a hinged 'leg' which is connected to a 'body mass' of 75lbs At the start of the test, the 75lbs acts directly downwards through the upright 'leg' and holds the test specimen in contact with a vinyl floor tile. The floor tile is moved (horizontally) forward at a standard speed (need to check method). As the floor moves forward the specimen remains in contact with the same part of the tile and so moves forward at the same speed. This base of the 'leg' also moves forward so that the 'body mass' begins to push the test specimen forward with slowly increasing strength. Eventually the 'body mass' is pushing on the test specimen with sufficient force to make it slip forward and this moment is recorded by the machine. This is a static method (outsole does not move) and can be used for Wet and Dry conditions.  Industry accepted minimum is .5 on both wet and dry vinyl tile surfaces.  Machine fixed in a place, i.e. stationery.  Method is reasonably objective because the test machine 'records' the result. There is a slight subjectivity in reading the machine but this is insignificant. There can be significant problems with preparation of the test specimen in some labs, it is very important that the specimen has a uniform thickness so that maximum ground contact is achieved. THIS METHOD WAS WITHDRAWN BY ASTM ON JANUARY 1, 2005.

Mark II, formerly ASTM F 1677-96

A test specimen (3” x 3”) cut from forepart of the outsole is mounted at the base of a 'leg' that has 10 lbs 'body mass' fitted to the top. The 'leg' is able to move up and down and can be locked in the up position where the test sample is floating just above the floor surface. The floor surface is a red quarry clay tile and is fixed within the base of the apparatus. With this tester, the top end of the 'leg' is moved to give steadily increasing 'leg angles'. The 'leg' is fixed into position at an angle to the floor surface and then the leg is released so that the test specimen drops into contact with the floor surface. If the friction is high enough the test sample will not slip on the floor surface. The angle of the leg is steadily increased until an angle is reached where when the leg is released, the specimen drops onto the floor and immediately slips because there is not sufficient friction between the specimen and the floor. The slip result is determined from the highest angle that the 'leg' can be released from without the test specimen slipping when it first strikes the floor surface.  This is a dynamic method and Wet and Dry conditions are used. Other surface conditions like oily, oily-wet and soapy can also be simulated.  Industry accepted standards are .5  dry, .4 wet, .3 contaminated.  This method has predominantly been respected in service industry – restaurants, food processing, beverage production.  Machine is portable, method is highly subjective in determining the point of slip.  THIS METHOD HAS BEEN WITHDRAWN BY ASTM THIS OCTOBER 1, 2006.

WTM 144-04

This is a Wolverine method and is identical to SATRA TM144:1999, using SATRA STM 603 slip testing machine.  The complete boot (or outsole) is tested in flat contact (children's sizes), forepart contact and heel strike test modes.  A 'body mass' of 101 lbs weight is used and heel strike mode is tested using a 5 degree angle.  Clay tile and EN ceramic tiles are routinely used although steel for industrial applications and a range of application specific surfaces such as boat decking and ice can be used for dry, wet and sodium lauryl sulphate  (100% chemical soap) contaminants. Computer controlled speed of surface movement, computer generated results, objective method. 

EN 13287-04

This method also uses SATRA STM 603 slip testing machine and at the moment is specifically for safety footwear only.  Differences are a higher load (112 lbs), a higher speed, a 7 degree angle for heel test and a slightly different method of data analysis. The EN safety test requires flat contact forward slip and heel strike test modes on EN ceramic tile that is wetted with a sodium lauryl sulphate soap solution . This method will be the only accepted method for safety, protective and occupational footwear outsole slip resistant testing in Europe as of January 2007. 

ASTM research has been under way in the USA to determine the best method for outsole slip resistance evaluation.  Major US safety and work footwear manufacturers have bought this SATRA 603 machine ($60,000 investment) in order to prepare for its expected future use.  No minimum standards have been established for the US market yet.