Rationale

ASTM E1820-25a uses the same symbol, Pmax, to indicate three different force-related quantities: • In 3.2.16 (Terminology) and Annex A17 (Fracture Toughness Tests at Impact Loading Rates Using Precracked Charpy-Type Specimens – namely, Note A17.1, Fig. A17.1, A17.5.2, and A17.9.2), Pmax indicates the maximum force recorded in an instrumented impact test. • In 7.4.5.2 (Fatigue Precracking) and Fig. 8 (Suggested Data Reporting Format), Pmax indicates the maximum force applied to the specimen during fatigue precracking. • In Annex A15 (Normalization Data Reduction Technique) – namely, A15.2.2, Pmax indicates the maximum force in the course of a fracture toughness test. NOTE that, in several other instances, the maximum force recorded during a toughness test is mentioned without using a symbol. This ballot aims at correcting this situation, by making the following changes: • The maximum force recorded in an instrumented impact test will be indicated by Fm, which is consistent with the symbol of maximum force in ASTM E2298 (Test Method for Instrumented Impact Testing of Metallic Materials). Consequently, the remaining force parameters obtained from an instrumented impact test will use “F” for force instead of “P” (i.e., Fgy, Fbf, and FY instead of Pgy, Pbf, and PY). • The symbol Pmax will be removed from A15.2.2 (the quantity is not used in any equation, so a symbol is not required). The symbol Pmax will be retained for indicating the maximum force in fatigue precracking. Suggested changes are highlighted using “Track Changes”.