If you are noticing variations in results from your tensile tests, and these cannot be attributed to the material under test, it is worth considering the condition of your test specimen gripping equipment. In particular grip faces e.g. face profiles on metal jaws, condition of rubber faced jaws and grip pressure activation systems e.g. springs, quality of pneumatic air or hydraulic oil – often these parts are consumable items and will wear over time. Regular servicing (preventative maintenance) and calibration is your best insurance that this type of problem should not occur during normal machine use, progressive and undetected wear of the gripping system faces is one of the biggest contributors to poor testing results. Remember that in almost all cases grip face wear will take place and regular checking and replacement (when necessary) should be a prerequisite of a proficient testing laboratory. For more information please contact the Tinius Olsen Help Desk on +44 (0) 1737 765001 o...
