The ASTM A370 standard proposes testing methods to determine the mechanical properties of steel, stainless steel and other related alloys. The purpose of this protocol is to evaluate the level of compliance of these materials with the specifications proposed by ASTM Committee A01.
This testing method is also available for other purposes, just like other mechanical testing ASTM standards. This means that it could be applied, for example, to evaluate components after their use in various tasks or to perform tests for acceptance by a buyer.
This standard measures the resistance of these materials to stretching or bending, as well as their hardness or stiffness when subjected to impacts of different kinds. Therefore, it offers a set of parameters that can be used to obtain accurate information, valuable for manufacturers and buyers, in regard to the specifications of a material and its capabilities.
How to perform ASTM A370
The mechanical testing methods outlined in ASTM A370 allow for determining the physical properties of tested materials. In order to obtain reliable, comparable and reproducible results, the protocol must be followed exactly as specified in the text published by ASTM. This text details how to perform the following tests:
- Brinell (Bending)
- Rockwell hardness test (which measures the resistance to indentation).
- Portable hardness testing
In addition to exact information about these tests (how to perform them and what results are appropriate to certify a product), the text contains annexes. These annexes specify different testing methods for bar and tubular metals, round wires and steel reinforcing bars.
ASTM A370 step by step
- Before starting with the testing method, the sample must be prepared. For this, the cross-sectional area of the smallest point is measured and calculated. Those not using an extensometer during the test will need to place the gage marks at this time, so that the elongation at the breaking point can later be measured.
- Once the correct functioning of the machine has been verified, the sample is installed on the system, and the extensometer is installed on the sample (provided that one is used, which is not mandatory).
- The test begins as per the specifications of ASTM A370 text mentioned above. Results will vary between the sample’s failure and its breakage. Once completed, the sample is removed from the system and, if an extensometer is not being used, its elongation is measured.
The ASTM A370 method outlines different types of results:
- Yield point: the moment when a material no longer behaves elastically and starts showing a plastic behavior. Elasticity means that, when subjected to the stress of a load, if it is removed, the material returns to its original shape. Conversely, a plastic behavior means that permanent deformations appear.
Measuring elasticity with this protocol is particularly important, because the Factor of Safety (FoS) must be clearly indicated for metallic materials and steel.
- Elastic limit: in this case, the purpose is finding an approximate value, since it is difficult to obtain an accurate result for this value using a universal testing machine. The standard arbitrarily establishes the value of this limit, which is 0.2% in the ASTM A370 protocol. While the elastic limit also measures the point at which a material stops behaving elastically, the yield point usually takes place beyond the elastic limit.
- Tensile strength: a material’s resistance to tensile forces before breaking.
- Elongation: it is the increase in length that takes place after the breakage of the material when compared to the original length.
Required machinery to comply with the standard
Certifying a product under the ASTM A370 standard is accomplished by using a universal testing machine, which can usually combine the application of tensile and compression forces, in addition to flexion and adhesion. In this case, it will also be necessary to have a machine that is capable of performing bending, hardness and impact tests.
There are multiple option to choose from when it comes to universal testers. Some companies opt for customized machines tailored to the needs of the material to be tested. Some of these options include high-speed testing, larger-than-average frames, or systems for materials that have larger elongation capabilities.
Likewise, the machines offer customization options to add more safety features, and offer process automation. Using these automated systems, it is possible to significantly reduce the need for operators, which in turn decreases the possibility of human error, reduces costs and improves the efficiency of the process. The system itself measures, loads, tests and removes the sample.
The universal testing machine must be capable of overcoming certain challenges posed by the ASTM A370 certification, such as correctly fastening the sample, measuring the elongation and cracks in the sample, and the ability to load heavy samples.
In addition to the universal testing machine, the use of clamps and flex fixtures to secure the sample is recommended.
Moreover, many companies choose to use an extensometer as an accessory. This machine is used to measure the deformation, pressure or load of a sample. It can therefore determine the ability of a material to change the nominal value of its strength when subject to different forces. For example, in the case of elongation, the extensometer specifies the change in length when compared to the initial length after forces have been applied.
Reasons to perform the ASTM A370 test
ASTM International is an organization of volunteers who generate standards for various industries, and is one of the largest and most important nonprofit organizations of its kind in the world. Its objective is to develop quality standards with the consensus of experts around the world across many areas of business and industries.
ASTM standards are therefore a collection of producer, consumer and researcher expertise, and government regulations. All of it is then reflected in technical documents such as the ASTM A370 method, which dozens of industries use as a basis.
Just like other testing protocols, the purpose of ASTM A370 is to generate standards to determine the characteristics of materials. In this case, its goal is to offer manufacturers of steel and other alloys the ability to certify their products as per the demands of the industry and their customers.
A few companies that might be interested in getting their products certified under this ASTM standard include company shipping departments, material manufacturers, and the automotive, aerospace or medical sectors, among many others.
Certification under the ASTM standards allows companies to:
- Guarantee the quality of their products based on global standards.
- Thoroughly know the properties of the materials, so that they can be improved via efficient processes.
To accomplish this, we design simulation systems that can comply with these protocols, so that companies can guarantee the safety of their product-packaging systems and save costs. If you are looking for solutions such as these, get in touch with us and let’s talk about how we can help you.