Rationale

ASTM E1820-24 allows three specimen geometries to be used: Single Edge Bend, SE(B), Compact, C(T), and Disk-Shaped Compact, DC(T). The SE(B) configuration, which is covered in Annex A1, may have a width-to-thickness ratio, W/B, between 1 and 4. However, the only drawing currently provided in the standard (Fig. A1.1) shows a SE(B) specimen with W = 2B, which is typically labelled as “B×2B SE(B) specimen”. Another very commonly used bend specimen configuration is the (precracked) Charpy-type specimen, with W = B = 10 mm, and therefore W/B = 1 (B×B SE(B) specimen). A drawing for this type of specimen already exists in ASTM E1921-24, and this ballot item proposes to add it to E1820 also, as Fig. A1.2. It is also proposed to remove the word “Recommended” from the caption of Fig. A1.1, and replace it with “with W/B = 2 (B×2B).” Finally, surface roughness in Fig. A1.1 has been converted from µin. to µm.