Tensile Testing is a daily routine test at ATRONA. We perform tensile testing for various industries on a large variety of components and raw material. Shape and size hardly matters with our vast capabilities. From small high speed diamond saws to a large 32" by 32" double column band saw with carbide blades. we can pretty much cut any size or shape. we have two full machine shops equipped to prepare tensile and charpy samples and turn projects around fast. If you are a steel mill looking for a lab that can handle multiple daily tests or a heat treater looking to certify heat treat lots we can help you meet your deadlines and goals fast and at affordable prices. Give us a call or visit us to see what we can do to help.
TENSILE TESTING: Equipped with state of the art software and five (5) tensile testers ranging in load capacity with various load cells and extensometers we can handle full size sampels and subsize samples. For sample preapration per ASTM A370, E8/E8M we have two full machine shops equipped with CNC capabilities and manular milling machines and lathes to handle large quantities of parts and samples. Our cutting capabilities include a total of eleven (11) small and large saws. We can help you with your routine tensile testing and certification needs. If you have a daily or routine tensile testing/reporting requirements we can be your one competitive and responsive laboratory source. Call us to inquire about the Mechanical and Tensile Testing services and programs we offer to steel companies, manufacturing companies, engineering groups, heat treaters, and testing laboratories.
WHY PERFORM A TENSILE TEST?
You can learn a lot about a material from tensile testing. As you continue to pull on the material until it breaks, you will obtain a complete tensile profile. A stress-strain curve will result showing how it reacted to the forces being applied.
Hooke's Law: For most tensile testing of materials, you will notice that in the initial portion of the test, the relationship between the applied force, or load, and the elongation the specimen exhibits is linear. In this linear region, the line obeys the relationship defined as "Hooke's Law" where the ratio of stress to strain is a constant, or E is the slope of the line in this region where stress (σ) is proportional to strain (ε) and is called the Modulus of Elasticity or Young’s Modulus.
MODULUS OF ELASTICITY: The modulus of elasticity is a measure of the stiffness of the material, but it only applies in the linear region of the curve. If a specimen is loaded within this linear region, the material will return to its exact same condition if the load is removed. At the point that the curve is no longer linear and deviates from the straight-line relationship, Hooke's Law no longer applies and some permanent deformation occurs in the specimen. This point is called the "elastic limit". From this point on in the tensile test, the material reacts plastically to any further increase in load or stress. It will not return to its original, unstressed condition if the load were removed.
YIELD STRENGTH: A value called “yield strength” of a material is defined as the stress applied to the material at which plastic deformation starts to occur while the material is loaded. Offset Method & Elongation For some materials (e.g., metals and plastics) the departure from the linear elastic region cannot be easily identified. Therefore, an offset method to determine the yield strength of the material tested is allowed. These methods are discussed in ASTM E8/E8M (metals) and D638 (plastics). An offset is specified as a % of strain (for metals, usually 0.2% from E8/E8M and sometimes for plastics a value of 2% is used). The stress (R) that is determined from the intersection point "r" when the line of the linear elastic region (with slope equal to Modulus of Elasticity) is drawn from the offset "m" becomes the “Yield Strength by the Off Set Method”. Elongation of the material after final rupture is then evaluated by extensometers registering the final length of the specimen and subtracting the initial length then dividing by the initial length multiplied by 100 to get the percentage of elongation.