Three Newly Revised Standards

MPMA is pleased to announce the publication of three new revisions to standards. ANSI/AGMA 6011-K25, Specification for High Speed Helical Gear Units, written by the AGMA High Speed Gearing Committee, ANSI/ABMA 20-2025, Radial Bearings of Ball, Cylindrical Roller and Spherical Roller Types - Metric Design, written by the ABMA ASC B3 committee, and ANSI/ABMA 4-2025, Tolerance Definition and Gauging Practices for Ball and Roller Bearings also written by the ABMA ASC B3 committee. ANSI/AGMA 6011-K25 ANSI/AGMA 6011-K25 includes design, lubrication, bearings, testing and rating for single and double helical external tooth, parallel shaft speed reducers or increasers. Units covered include those operating with at least one stage having a pitch line velocity equal to or greater than 35 meters per second or rotational speeds greater than 4500 rpm and other stages having pitch line velocities equal to or greater than 8 meters per second. Changes in the 2025 edition include: Clause 5.5 was expanded to apply allowable stress numbers for case hardened gears at 55 HRC minimum, and similar values were reintroduced from AGMA 421.06. In the lubrication section the maximum allowable filtration values as defined in ISO 4406 were tightened and the minimum recommended helix angle was increased. In Annex B, the derating factor was assigned to pitch line velocity limits in calculating the load function. The Annex D example problem was expanded to provide examples for both through hardened and case carburized gears. And formula calculations have been added to the summary tables for guidance on how the calculations should be applied. ANSI/ABMA 4-2025 ANSI/AGMA 4-2025 includes terms and definitions of tolerances for the boundary dimensions, running accuracy and internal clearance of ball and roller bearings listed in other ABMA and ISO standards, as well as includes descriptions of methods of measuring, which are commonly used by bearing users and which, as a rule, give an accuracy sufficient for practical purposes. The 2025 revision was updated to align symbols and definitions to ISO nomenclature, redraw the figures for readability, and align the formatting to the current ABMA style. ANSI/ABMA 20-2025 ANSI/AGMA 20-2025 specifies boundary dimensions, tolerances and radial internal clearances for metric radial ball, cylindrical roller, and spherical roller bearings in common usage in the United States.

The 2025 revision was updated to align symbols and definitions to ISO nomenclature, redraw the figures and tables for readability, and align the formatting to the current ABMA style. On behalf of the bearing and gearing industry, MPMA would like to extend a sincere appreciation for the participation and the valuable contributions of the following experts. In addition, MPMA would like to especially thank the companies of these experts whose foresight and generosity made their participation possible.