AGMA Technical Division has released AGMA 945-2-B20, Splines - Design and application (Inch Edition).  

This information sheet covers inch based parallel straight sided and involute splines. It provides information relating to geometry, fit types, materials, manufacturing, rating, inspection, lubrication, and failure of splined elements. For metric based splines see AGMA 945-1-B20.

The scope of this information sheet includes involute splines (some of which are governed by ANSI B92.1), plus variants such as modifications to helix, lead crown, form diameters, root geometry, tooth thickness, and fits and straight sided splines with parallel teeth in the external spline (some of which are governed by SAE J499 or SAE J501). It also includes longitudinal effects such as the washout of the minor diameter in splines that are formed or cut into a shaft and hoop strength effects of hollow splined sections. A limited range of materials is included: hard steel, soft steel, powdered metal steel (PM), and cast iron. Manufacturing processes discussed include: rolling, hobbing, shaping, milling, broaching, grinding, net formed PM, and cold forming. Rating for compressive, shear, bending, and hoop stresses are covered, as are tolerances, lubrication, and failure modes. Both elemental and attribute inspection of splines are included. It also describes drawing requirements, and a troubleshooting guide.

Several documents exist relating to various aspects of spline design and manufacture. For example, spline geometry is well covered in other standards and rather than repeating those standards, this document makes reference to each one. Even the term spline can refer to a multitude of part shapes. This document is an attempt to augment other spline standards and consolidate information on spline types, geometry, assembly, inspection, materials, manufacturing processes, lubrication, rating, and failure modes.

Although involute splines of 30° pressure angle are very popular, this information sheet also covers involute splines of 37.5° and 45° pressure angle, parallel straight sided splines and modifications to spline geometry such as lead modification, missing tooth, and end geometry from the manufacturing process.

This information sheet is an extension of AGMA 945-1-B20 to cover inch based splines. Heat treatment requirements were updated, the rating and troubleshooting clause was separated, and new references were added. The committee began work on this information sheet in August 2019.  

The first draft of AGMA 945-2-B20 was created in May 2020. It was approved by the membership in August 2020 and approved for publication by the Technical Division Executive Committee (TDEC) on August 20, 2020.