Standards in gears is relational to certain values of parameters in figures, like length, mass, angle etc. Officially certified measuring instruments must be checked for accuracy using such standards. Using a standard has some advantage, the primary being an agreement to the degree of quality of gears among trading partners. They can pass on that understanding of quality to customers.

Metric Standards
Metric roller chain and sprockets are classified according to ISO standards 606. The number correlates to pitch in 1/16" increments, expressed in millimeter units. An ISO 12 sprocket mates with a chain with ¾" or 19.05mm, pitch. Number of teeth for a specified pitch will determine sprocket size and drive ratio.

The SAE Aerospace Standard (AS) establishes the standard modules for aerospace metric involute gear teeth and establishes the tooth dimensions of aerospace metric involute gear teeth in terms of the conjugate rack type cutter whose counterpart reference profile is called the basic rack profile of the generated gear, having the tooth dimensions expressed in terms proportional to the module.

SAE also covers established metric manufacturing tolerances applicable to corrosion and heat resistant steel, iron alloy, titanium and titanium alloy bars and wire ordered to metric dimension.

British Standards
English standards are classified according to ANSI number designations. Sprockets engage chains in many different power transmission and conveyor system. English roller chain and sprockets are categorized according to ANSI B 29.1M. The number can be used to identify pitch. The first digits identify the pitch in 1/8" increments and the last digit is 0 for standard proportions, 1 for lightweight chain and 5 for roller less bushed chain.

AGMA Standards
AGMA is an accredited standards development organization with the American National Standard Institute that produces quality consensus standards designed to meet the demand of domestic and the international markets. AGMA hold the position of Secretariat of ISO Technical Committee and promotes a better understanding of the concerns of American gear manufacturers, as well as wider acceptance of AGMA standards. The association also promotes the dissemination of research and development work conducted throughout the industry related to gear design and manufacture at major meetings and seminars.

The standard method for determining induced bending stresses in bevel gears comes from the AGMA. Gears shall be designed in accordance with the AGMA standards 211.02 and 221.02. Bearings shall be ball or roller type and shall be selected in accordance with AGMA standards 265.01. The aerator shall be stainless steel of adequate size to transfer the applied torque and to resist bending. To maximize strength and performance the rotor shall be one piece molded fiberglass of monolithic construction and internally reinforced with a steel structure.

AGMA gear quality numbers range from 3 to 15 and identify the accuracy level of the tooth element tolerances that are permissible in the manufacture of each particular gear in terms of its specialized use. The permissible tolerances for the different quality numbers may be obtained from AGMA standards, which show the type of gear and the permissible tolerances and inspection dimensions.