The formulae specified in this International Standard are intended for the establishment of a uniformly acceptable

method for calculating the pitting resistance and bending strength capacity for the endurance of the mainpropulsion

and auxiliary gears of ships, offshore vessels and drilling rigs, having straight or helical teeth and subject

to the rules of classification societies.

The rating formulae in this International Standard are not applicable to other types of gear tooth deterioration, such

as plastic yielding, micropitting, scuffing, case crushing, welding and wear, and are not applicable under vibratory

conditions where there may be an unpredictable profile breakdown. The bending strength formulae are applicable

to fractures at the tooth fillet, but are not applicable to fractures on the tooth working profile surfaces, failure of the

gear rim, or failures of the gear blank through web and hub. This International Standard does not apply to teeth

finished by forging or sintering. This standard is not applicable to gears having a poor contact pattern.

This International Standard provides a method by which different gear designs can be compared. It is not intended

to assure the performance of assembled drive gear systems. It is not intended for use by the general engineering

public. Instead, it is intended for use by the experienced gear designer who is capable of selecting reasonable

values for the factors in these formulae based on knowledge of similar designs and awareness of the effects of the

items discussed.

WARNING — The user is cautioned that the calculated results of this International Standard should be

confirmed by experience.