scope:

This standard is applicable to marine gearing made from steel forgings, bar stock and castings intended for main propulsion service over 1500 horsepower. Alloy steel specifications and quality assurance measures presented represent the state of the art and are not intended to assure the performance of subject assembled marine gear drive systems.

This standard pertains to through hardened gearing, as well as carburized, nitrided and induction contour surface hardened gear teeth of pinions and gears. This standard presents the properties of commonly available alloy steels used for marine gearing. It is recognized that modifications of these alloys and other suitable alloy steels are available which may be used in marine gearing. It does not address other forms of surface hardening, such as flame hardening and spin coil induction hardening.

Requirements for Quality Grades 1 and 2 are defined in this standard. Although reference is made to Grade 3 melting practice for carburized steels, the experiencewith the use of these steels is limited and therefore outside the scope of this standard.

This standard is intended for use by those experienced in gear design or manufacture. It is not intended for use by the engineering public at large.