(WITHDRAWN; replaced by 915-1-A02, 915-2-A05, 2015-1-A01, and 2015-2-A06)

SCOPE
This Standard establishes a classification system which may be used to communicate geometrical quality specifications of unassembled external and internal involute gearing. It provides a designation system for quality, materials, and heat treatment of spur, helical (single or double), and herringbone gears. It also provides information on measuring methods and practices. This Standard provides the gear manufacturer and the gear buyer with a mutually advantageous reference for uniform tolerances and inspection procedures. Thirteen classes of quality levels are defined in this Standard, numbered Q3 through Ql.5, in order of increasing precision.

Equations for Tolerances
Equations for tolerances are provided for those who wish to compute the tolerances that define the quality of gearing in Section 5. The equations yield the same values as the tables. The accuracy tolerance formulas are valid for gears of a minimum size of 6 teeth through a maximum size of the lesser of 1200 teeth or 400 inches (10 000 mm) pitch diameter.

Tolerance TabIes
Tolerance tables derived from the equations are provided which show the maximum values that are allowed by the specific Quality Number for a gear in Section 6. The tolerance tables in this Standard list the formula values for diametral pitches 0.5 through 120 (modules 50 through 0.2), and for gears ranging in numbers of teeth from 6 through 200.

Tolerance for Master Gears
Tolerances which define levels of quality for master gears are provided in Section 8.

Measuring Methods and Practices
Measuring methods and practices are included in order to promote uniform inspection procedures (see Section 9). These methods permit the user to conduct measuring procedures which are accurate and repeatable to a degree compatible Kith the specified quality. Experienced personnel, with calibrated instruments in suitable surroundings, are required.

Materials and Heat Treatment
A designation of the required material and heat treatment can be included as a part of the AGMA Classification Number. Designation numbers are provided which identify gear materials, heat treatments, and hardness ranges (see Section 7).

Exceptions
This Standard does not apply to enclosed gear unit assemblies, including speed reducers or increasers, gear motors, shaft mounted reducers, high speed units, or other enclosed gear units which are sold on a rated horsepower basis for a given speed, ratio, or application. Gear design and backlash is beyond the scope of this Standard. Refer to the latest AGMA Publications Index for applicable standards. This Standard does not apply to gears larger than 400 inches (10 000 mm) in pitch diameter, or larger than 10 inches (250 mm) in face width, (per helix, if double helical or herringbone) ; or helix angles exceeding 45 degrees.

NOTE: Tolerance values for gears outside the limits stated in this Standard should be established by determining the specific application requirements. This may require setting a tolerance smaller than calculated by the formulas in this Standard, particularly for tooth alignment of gears with face widths over 10 inches (250 mm).

FOREWORD
[The foreword, footnotes, and appendices are provided for informational purposes only, and should not be construed as a part of American Gear Manufacturers Association Standard 2000---A88, Gear Classification and Inspection Handbook.]

This Handbook provides tolerances for different gear quality levels from Q3 to Q15 for unassembled spur and helical gears. It further describes methods and practices for measuring the various gear elements for which tolerances are provided. Applicable definitions are provided.

The purpose is to provide a common basis for specifying quality, and for the procurement of unassembled gears. It is not a design manual for determining the specific quality levels for a given application. It is not intended for use as a reference in procurement of enclosed drives.

The AGMA Standard 390.03 was published in 1973 as a consolidation and updating of several withdrawn AGMA publications, including:

• AGMA 235.02 (Feb., 1966), Information Sheet for Master Gears
• AGMA 239.01 (Oct., 1965), Measuring Methods and Practices Manual for Control of Spur, Helical and Herringbone Gears
• AGMA 239.01A (Sept., 1966), Measuring Methods and Practices Manual for Control of Bevel and Hypoid Gears, and parts of
• AGMA 236.04(05), Inspection of Fine---Pitch Gears
• AGMA 390.02 (Sept., 1964), Gear Classification Manual originally published as AGMA 390.01 (1961)

Data was added for Gear Rack and Fine---Pitch Worms and Wormgears. The former separate sections of AGMA 390.02 for Coarse---Pitch and Fine---Pitch spur, Helical and Herringbone Gearing was blended to offer a single, compatible classification system The tolerance source identifier “Q” was added to indicate that the tolerances in 390.03 apply. If Q is not used as a prefix in the quality number, tolerances in AGMA 390.01 and 390.02 apply.

This Handbook is an update of those sections from AGMA 390.03 for parallel axis gears only. Additionally, the formulas have also been developed to derive the tolerances in metric terms. The format of the tolerance tables has been revised for improved presentation but basic tolerance levels are unchanged from AGMA 390.03. The other material in AGMA390.03 on Bevels, Racks and Worms is not covered here, and is left unchanged in AGMA 390.03.

A revision of 390.03 was initiated by a joint panel of representatives of AGMA and General Motors Corporation, meeting from 1975 to 1977. Subsequently, it was revised by personnel of the AGMA Gear Classification Handbook Committee as AGMA 2000. This version was approved by AGMA membership in January 1988 and as a American National Standard Institute (ANSI) standard on March 31, 1988*.

PLEASE NOTE THAT THIS STANDARD HAS BEEN WITHDRAWN and has been replaced by 915-1-A02, 915-2-A05, 2015-1-A01, and 2015-2-A06

ISBN: 1-55589-495-X 

Pages: 156