In the evaluation of crushers, t-family curves obtained from single particle test methods are frequently used. It is known that there are many difficulties and problems in these tests. In this study the breakage behaviour of three different limestones in an impact crusher was investigated. A new size distribution model was developed by t-family value evaluation and Bond work index approach. As a result, the validity of the equation was proved by a high regression value (r(2) = 0.88). (C) 2010 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.