What is this standard about?
This is the second in a three part standard on the mechanical testing of metals to test their toughness using the Charpy impact test.
The first part outlines the test method. This part covers how to verify testing machines, and the third part, how to prepare Charpy V-notch test pieces for indirect verification of pendulum impact machines.
Who is this standard for?
The Charpy impact test is applied in a very wide range of industries. This standard will be used by metallic material manufacturers, purchasers and testers in those industries.
Why should you use this standard?
It can happen that two machines evaluated by direct-verification procedures give significantly different impact values when testing test pieces of the same material. Since this difference can lead to commercial disagreements, some purchasers of materials require that all pendulum impact testing machines are indirectly verified by testing reference test pieces supplied by them. A machine is considered acceptable only if the values obtained agree, within specified limits, with the values furnished by the reference test pieces. This part of ISO 148 describes both the original direct verification and the indirect verification procedures.
It covers the verification of pendulum-type impact testing machines in terms of their constructional elements, their overall performance and the accuracy of the results they produce.
It applies to machines with 2 mm or 8 mm strikers used from pendulum impact tests carried out, for instance, in accordance with ISO 148-1.
It describes two methods of verification:
- The direct, static, method, involves measurement of the critical parts of the machine to ensure that it meets the requirements of this part of ISO 148. Instruments used for the verification and calibration are traceable to national or international standards.
- The indirect, dynamic, method, uses reference test pieces to verify points on the measuring scale for absorbed energy. The requirements for the reference test pieces are found in ISO 148-3.
What’s changed since the last update?
The standard was systematically reviewed by technical experts to ensure its continued market relevance. This standard is a technical revision of the 2008 version which has been withdrawn.
