BS ISO 3547-7-2020 Plain bearings – Wrapped bushes Part 7: Measurement of wall thickness of thin-walled bushes.
This document describes, following ISO 12301, the checking methods and measuring equipment used for measuring the total wall thickness of thin-walled bushes in the finished state.
NOTE All dimensions in this document are given in millimetres.
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 12301, Plain bearings — Quality control techniques and inspection ofgeometrical and material quality characteristics
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
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3.1 wall thickness
radial distance between the opposing measuring points at the inner and outer cylindrical surface
Note I to entry: See Figure 1.
4 Symbols and units
For the purposes of this document, the symbols and units given in Table 1 apply.
5 Purpose of checking
The purpose of checking is to ensure that the wall thickness and wall thickness tolerances are in accordance with ISO 3547-1. If this measurement is required, it is designated by S3; see ISO 3547-1.
6 Checking methods
6.1 Measuring principle
The gauging axis of the measuring device shall be in the radial direction and perpendicular to the outside surface of the test piece in order to find the minimum value of the wall thickness. The measured values may be recorded by a single measurement or by a sum measurement, as represented symbolically in Figure 2.
The presence of lubricating holes, oil pockets, oil grooves, markings or special chamfers can require deviation from the measuring lines and measuring points specified in 6.2 and 6.3. Any such deviation shall be agreed between customer and supplier.
Any wall thickness not conforming to the specified values due to the manufacturing process, because of deformation of the bearing backing in the area of marking or at non-load-bearings places of wrapped bushes, shall be agreed between customer and supplier.
6.2 Line measurement around the circumference
Continuous measurement of the wall thickness around the circumference shall be carried out at the measuring lines specified in Figure 3 and Table 2.BS ISO 3547-7 pdf download.