RE: impact strength unit conversion

From: John Male (
Date: Wed May 17 2000 - 18:22:29 EEST


While both the Izod and Charpy tests provide a measure of the energy absorbed in an impact test, the way in which the test piece is supported, and the dimensions of the sample and the notch in it are different. I do not believe that there is a direct correlation between the energy values obtained from each of the tests. The differences in the tests should be outlined in most mechanics books (e.g. Benham and Crawford - Mechanics of Engineering Materials).

I know this doesn't really help. If you are particularly interested in impact strength, the best thing to do might be to get identical samples made and test them using the same method.

John Male

Advent Communications Ltd

-----Original Message-----
From: Nigel Warden []
Sent: Wednesday, May 17, 2000 2:32 PM
Subject: impact strength unit conversion

Dr Igor Shishkovsky,

Thankyou for replying to my question. I am not quite sure what your reply is
telling me though.

I have an example of what I am trying to achieve.

American standard ASTM D256:-
Impact strength test (Notched Izod) on laser sintered Polyamide material
supplied by DTM corp. provides a result of 214 J/m.

European standard DIN 53453:-
Notched impact strength test (Charpy) on laser sintered Polyamide material
supplied by EOS (GmbH) provides a result of 3 kJ/m2.

How can I convert the EOS result into the same units as the DTM result?

Which has the greater impact strength?


Nigel Warden

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