Plastic Tensile Test Specimen Dimensions

A universal testing machine tensile testing machine is needed to perform this test.
Plastic tensile test specimen dimensions. The preferred specimens are dumbbell shaped specimens types 1a injection molded and 1b machined. Type i specimens have an overall length of 165 mm and width of 13 mm with a gauge length of 50 mm. Specimens for astm d638 are dumbbell shaped with either a 25 mm or 50 mm gauge length. The thickness and width of the specimen is normally determined by a micrometer screw with a ratchet.
The ratchet limits the measurement force to 5 to 15 n. A 50 mm gauge length is recommended. Tensile testing also known as tension testing is a fundamental materials science and engineering test in which a sample is subjected to a controlled tension until failure. While there are differences in length between these two specimen types they share a nominal width of 10 mm and thickness of 4 mm.
The contact surface is flat and circular with a diameter of 6 35 mm. There are six possible specimen sizes for testing to iso 527 2. Properties that are directly measured via a tensile test are ultimate tensile strength breaking strength maximum elongation and reduction in area. In automated systems the thickness and width is determined by a cross section measuring device.
1 2 this test method is applicable for testing materials of any thickness up to 14 mm 0 55 in. Astm d638 is one of the most common plastic strength specifications and covers the tensile properties of unreinforced and reinforced plastics. Gauge length changes with astm e83 class b 2 accuracy. The type iv specimen shall be used for testing nonrigid plastics with a thickness of 4 mm 0 16 in or less.
However for testing specimens in the form of thin sheeting including film less than 1 0 mm 0 04 in in thickness astm standard d882 is the preferred test method. From these measurements the following properties can also be determined. An absolute accuracy of 10 μm for a 50 mm gauge length and relative accuracy within 0 5 are required by astm d638 for measuring the tensile modulus of elasticity. This test method uses standard dumbell or dogbone shaped specimens under 14mm of thickness.