ISO 4156-3-2021 pdf – Straight cylindrical involute splines — Metric module, side fit — Part 3: Inspection.
1 Scope This document provides data, guidance and requirements for the inspection of straight (non-helical) side fitting cylindrical involute splines. Limiting dimensions, tolerances, manufacturing deviations and their effects on the fit between connecting coaxial spline elements are defined and tabulated. Linear dimensions are expressed in millimetres and angular dimensions in degrees. 2 Normative references The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 3, Preferred numbers — Series of preferred numbers ISO 1101, Geometrical product specifications (GPS) — Geometrical tolerancing — Tolerances of form, orientation, location and run-out ISO 1938-1, Geometrical product specifications (GPS) — Dimensional measuring equipment — Part 1: Plain limit gauges of linear size ISO 4156-1, Straight cylindrical involute splines — Metric module, side fit — Part 1: Generalities ISO 4156-2, Straight cylindrical involute splines — Metric module, side fit — Part 2: Dimensions ISO 5459, Geometrical product specifications (GPS) — Geometrical tolerancing — Datums and datum systems 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 4156-1 apply. ISO and IEC maintain terminological databases for use in standardization at the following addresses: — ISO Online browsing platform: available at https:// www .iso .org/ obp — IEC Electropedia: available at http:// www .electropedia .org/
5 Reference conditions The standard reference temperature for industrial length measurements is 20 °C. The dimensional requirements for parts and gauges are defined at that temperature and inspection shall also normally be carried out at that same temperature. If measurements are taken at another temperature, the results shall be corrected using the expansion coefficients of parts and gauges respectively. Unless otherwise specified, all measurements shall be made under zero measuring load. If measurements are made under a non-zero load, the results shall be corrected accordingly. However, such correction is not required for comparison measurements made with the same comparison means and under the same measuring load, between similar components of the same material and with the same surface condition. 6 Quality features 6.1 General The inspection of splines is divided into three quality features, as shown in Figure 1. To specify the location ISO 1101 and ISO 5459 shall be used. For form and size ISO 4156-1 and ISO 4156-2 apply.
18.104.22.168 Variable sector gauge The variable sector gauge measures the actual circular tooth thickness or space width. The actual measurement is achieved using radially locking left- and right-hand flanks and comparison to a master having a known tooth thickness or space width. 7.1.4 Effective size 22.214.171.124 GO composite gauge GO composite gauges are used to check a) that the specified effective limits of tooth thickness or space width are not exceeded at the maximum material condition of the part, b) the specified form diameter of the part, thus ensuring that the required tolerances are controlled for the full involute depth, and c) the specified length of engagement, thus ensuring that the spline maximum material limit has not been exceeded. 126.96.36.199 Variable composite gauge The variable composite gauge measures the effective size of tooth thickness or space width. The actual measurement is achieved using the radially locking left- and right-hand flanks and comparison to a master having a known tooth thickness or space width. 188.8.131.52 NO GO composite gauge The NO GO composite gauge is used to check the specified effective limit of minimum tooth thickness or maximum space width, where the gauge contacts only at the ends. 184.108.40.206 Inspection of diameter at tooth tip (D ii or D ee ) All these inspection methods require measuring the tooth tip (internal minor diameter, D ii , or external major diameter, D ee ) using GO and NO GO plain (plug or ring) gauges or other acceptable measuring devices.