Tuesday, February 23, 2010

Spec Sheets

Of all the tasks that I have to undertake, looking through spec sheets is just about at the bottom. It has to be for everyone too, right? How's this for a starter list:
  1. What properties are listed varies from sheet to sheet.
  2. What test procedures were followed varies. Sometimes it's an ISO standard, sometimes it's an ASTM, sometimes it's an internal procedure. Plus there are plenty of user industries that have their own tests such as the SAE, PSTC...Consider impact testing. There are the notched, unnotched, and reverse notched Izod tests, (the ISO test output is energy/area, while the ASTM is energy/length), the various Charpy tests, the Multi-Axial Instrumented Impact Energy test, a whole gamut of temperature conditions...
  3. The whole metric-English unit dichotomy.
  4. The inadequacies of the test designs in general. Melt-flow is a disaster, heat deflection temperature under load is representative of nothing...
Rectifying the situation is not possible. Despite the ever increasing consolidation within the industry, any hope for standardization is futile. The best one can hope for is that standard test procedures are used, ISO, ASTM or whatever.

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