ISO/NP 12135 http://www.iso.org ISO standards and projects ISO - International Organization for Standardization 240 http://www.iso.org/iso/logo_iso.gif http://www.iso.org ISO/NP 12135 ISO/NP 12135 - Metallic materials -- Unified method of test for the determination of quasistatic fracture toughness This document reached stage 10.99 on 2011-09-19 , TC/SC: ISO/TC 164/SC 4, ICS: 77.040.10 Standards under development