DIN ISO 14635-3:2025-04

This document specifies a test method based on a FZG four-square test machine for determining the relative load-carrying capacity of semi-fluid gear greases defined by the gear surface damage known as scuffing. This method is useful for evaluating the scuffing load capacity potential of semi-fluid gear greases of NLGI classes 0 to 000, typically used with highly stressed gearing for enclosed gear drives. It can only be applied to greases giving a sufficient lubricant flow in the test gear box of the FZG test machine. This standard differs from DIN ISO 14635-3:2011-08 as follows: a) references to ISO 1328-1:1995 have been dated as this document uses an accuracy grade which is numerically different from the tolerance class in ISO 1328-1:2013; b) ISO 4287 is no longer referenced as it has been withdrawn, and replaced by ISO 21920-2; c) ISO 4964 is no longer referenced as it has been withdrawn, and similar information can be found in ISO 18265; d) in Table 1, the symbol for "specific sliding" has been corrected according to ISO 21771; e) some bibliographic entries for standards which were withdrawn have been replaced, and changes have been made from dated to undated references; f) in subclause 5.2, the wording has been harmonized with the DIN ISO 14635 series; g) n Clause 9, the reporting value of the specific weight loss has been corrected. This document contains the English translation of the International Standard ISO 14635-3:2023, which has been prepared by Technical Committee ISO/TC 60 "Gears", Subcommittee SC 2 "Gear capacity calculation", the secretariat of which is held by DIN (Germany). The responsible German standardization committee is Working Committee NA 060-34-19 AA "Zahnradschmierung und Schmierstoffe" ("Gears lubrication and lubricants") of Technical Section "Drive technology" at DIN Standards Committee Mechanical Engineering (NAM).