Work Item
ASTM WK90001
Revision of E1820-23b Standard Test Method for Measurement of Fracture Toughness
Rationale
The current section 6.5.2.2 of ASTM E1820-23b states “The critical tolerances and suggested proportions of the clevis and pins are given in Fig. 5.”, however this figure does not contain any information about dimensions or tolerances of the loading pins. The same Fig. 5 presents several issues, some of which editorial, which need to be addressed.
A completely revised Fig. 5 in GD&T (Geometric Dimensioning & Tolerances) format is proposed in this ballot. It is planned to convert other figures in E1820 to this format. Several new Notes have been added below the figure, with useful information and recommendations for the user.
Furthermore, two new sections are proposed for the Annexes on C(T) (section A2.1.3) and DC(T) (section A3.1.3) specimens, providing dimensions and tolerances for specimen holes and loading pins for both specimen geometries. Dimensions and tolerances are provided in the new Table A2.1, as a function of specimen width W and specimen thickness B. The aim of the new sections and the new Table is to avoid interferences between loading pins and specimen holes, as well as excluding unrealistically small tolerances for thicknesses 12.7 mm or smaller. All the figures in this ballot have been generally “cleaned up”.
This item has gone through four previous ballot rounds, receiving every time persuasive negatives and several comments. All changes with respect to the current E1820-23b sections are highlighted using “Track Changes”.
Work Item Status
Date Initiated: 03-14-2024
Technical Contact: Enrico Lucon