Safe Woodcutters Guide 11

Test Of Protective Garments

The APA Standard gives a "required minimum area of protection on pants and chaps" (the minimum area covered by the protective pads). The Standard requires that a garment will be able to resist cutthrough by a saw chain moving at a speed of 3.000 feet per minute, tested at both 45° and 90° to the longitudinal axis of the test specimen.
The American Society for Testing Materials (ASTM) has developed a standard test method entitled "Cut Resistance to Chain Saws of Lower Body (Legs) Protective Garments".

(Designation: F 1414-92a/ 1992/1993)

Summary of Test Method

Test speciments are securely mounted on a test apparatus which simulates a human leg
A chain saw of specific characteristic and operating at a designed speed, is brought into contact with the test specimen.
The cutting action of the saw will achieve one of three results; (1) complete cut through, (2) no cut through after 1,5 sec. or (3) complete chain stop.
Data collection of cut resistance and TSS is measured electronically by means of wires placed on the top and the bottom of test specimen to measure cut through time and an electronic means to measure chain speed just prior to contact with test specimen and after contact is initiated.

(The foto shows the test rig for testing resistance to cutting by a chain saw at The Swedish Testing Institute.)

TSS: Threshold Stopping Speed
= The maximum saw chain speed (m/s, f/m) that does not produce a cut through when the chain saw is dropped onto the test specimen.

The Minimun Threshold Stopping Speed
= 3000 fpm (feet per minute)
= The minimum speed of the saw chain, at which a leg protection with a protective pad shall be able to avoid a cut through and protect what's covered, when the saw chain is dropped onto it in a way "in accordance with ASTM standard test method for measurement of cut resistance to chain saw in lower body (legs) protective garments".

If a leg protection can avoid a cut through at a higher Threshold Stopping Speed, (at a higher speed of the saw chain whern the saw chain is dropped in the test), the higher the level of the protection.

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Test Of Protective Garments
The APA Standard gives a "required minimum area of protection on pants and chaps" (the minimum area covered by the protective pads). The Standard requires that a garment will be able to resist cutthrough by a saw chain moving at a speed of 3.000 feet per minute, tested at both 45° and 90° to the longitudinal axis of the test specimen. The American Society for Testing Materials (ASTM) has developed a standard test method entitled "Cut Resistance to Chain Saws of Lower Body (Legs) Protective Garments". (Designation: F 1414-92a/ 1992/1993) Summary of Test Method Test speciments are securely mounted on a test apparatus which simulates a human leg A chain saw of specific characteristic and operating at a designed speed, is brought into contact with the test specimen. The cutting action of the saw will achieve one of three results; (1) complete cut through, (2) no cut through after 1,5 sec. or (3) complete chain stop. Data collection of cut resistance and TSS is measured electronically by means of wires placed on the top and the bottom of test specimen to measure cut through time and an electronic means to measure chain speed just prior to contact with test specimen and after contact is initiated. (The foto shows the test rig for testing resistance to cutting by a chain saw at The Swedish Testing Institute.)	TSS: Threshold Stopping Speed = The maximum saw chain speed (m/s, f/m) that does not produce a cut through when the chain saw is dropped onto the test specimen. The Minimun Threshold Stopping Speed = 3000 fpm (feet per minute) = The minimum speed of the saw chain, at which a leg protection with a protective pad shall be able to avoid a cut through and protect what's covered, when the saw chain is dropped onto it in a way "in accordance with ASTM standard test method for measurement of cut resistance to chain saw in lower body (legs) protective garments". If a leg protection can avoid a cut through at a higher Threshold Stopping Speed, (at a higher speed of the saw chain whern the saw chain is dropped in the test), the higher the level of the protection.