Tension and Compression Testing
CMS is ISO/IEC 17025:2005 accredited for tensile testing. Our facility has four (4) test machines that are dedicated to testing tensile specimens. Of these four test machines, two have a 60,000 lbf maximum load capacity, which is implemented in both tension and compression loading of specimens. These two test machines are the CMS mechanical testing department's workhorses, as the ultimate tensile strength of most standard tensile specimens lies within the maximum load capacity of these machines. The largest tensile machine at the CMS facility has a 160,000 lbf maximum load capacity and is implemented in both tension and compression loading of specimens; this machine can perform tensile testing of specimens with an ultimate tensile strength that requires loading above 60,000 lbf, as well as full-size bolt testing.
All of our tensile machines are fitted with digital acquisition systems for acquiring testing data. CMS has additional load cells for lower loads at 10,000 lbf - 1,000 lbf – 100 lbf – 10 lbf.
Tensile testing procedures at the CMS facility are preformed in accordance with ASTM standard specifications, such as:
ASTM E8 (Standard Test Methods for Tension Testing of Metallic Materials)
ASTM A370 (Standard Test Methods and Definitions for Mechanical Testing of Steel Products)
ASTM B557 (Standard Test Methods for Tension Testing Wrought and Cast Aluminum- and Magnesium-Alloy Products)
ASTM F606 (Standard Test Methods for Determining the Mechanical Properties of Externally and Internally Threaded Fasteners, Washers, Direct Tension Indicators, and Rivets)
Full-size Tension Testing Bolts—This testing process involves straight axial force being applied to the bolt without using a controlled testing section (machining a reduced location on the sample). To meet this test's requirements, the bolt shall support a specified load before fracture, not less than the minimum tensile strength specified in the product specifications for the given bolt's size and grade. This call-out can be specified in force loads (lb) or cross-sectional area loads (psi).
Wedge Tension Testing of Bolts—This testing process is to determine the bolt still meets the bolt's ultimate load requirements with the placement of a wedge under the bolt head. The wedge angle depends on the size of the bolt being tested and is determined according to table 2 of ASTM-F-606. The bolt shall be tension tested to fracture. To meet this test's requirements, the bolt shall support a load before fracture not less than the minimum tensile strength specified in the product specification for the applicable size, grade, and thread series.
Tension Testing of Machined Test Specimens—This testing process requires the bolt to have a controlled section machined in the bolt. Requirements for passing testing of machined location give all properties of the bolt being tested, including Yield Strength, Elongation, and Ultimate Strength. To meet this test's requirements, the bolt shall meet minimum tensile strength, yield strength, and elongation properties specified in the product specification for the applicable size, grade, and thread series.