Method 3111 is a Tearing Strength test for cable sheath materials. This method is intended for determining the resistance to tear of sheath compounds and is applicable to the usual grades of rubber and thermoplastic compounds used for sheaths.
The specimen is a piece of sheath taken from the inspection unit, cut to the shape and dimensions shown in figure 3111. The thickness at the enlarged end shall be not greater than 0.150 inch and not less than 0.040 inch. The specimen is prepared using a die as described in method 3021.
The specimen is cut with the grain running the long way of the specimen. It is 2 inches long with the reduced portion 0.5 inch wide and the enlarged portion 1.5 inches wide. The tearing strength is the median of results from specimens tested.