ISO 4287

ISO 4287
Title	ISO 4287
Number	ISO 4287
Year start	1997
Version	2019
Organization	International Organization for Standardization
Committee	ISO/TC 213
Related	ISO 3274, ISO 4288, ISO 13565
Domain	Geometrical product specifications
Status	Current

ISO 4287 is an international standard published by the International Organization for Standardization that defines the terms, definitions, and parameters for the measurement of surface texture. It is a foundational document within the field of geometrical product specifications, providing the essential vocabulary and conceptual framework for characterizing the deviations of a real surface from its ideal form. The standard is maintained by technical committee ISO/TC 213 and is crucial for ensuring unambiguous communication in manufacturing, quality control, and metrology across global industries.

Overview

The standard establishes a coherent system for describing surface texture based on profile method measurements, distinguishing between various components such as roughness, waviness, and primary profile. It was first published in 1997, with subsequent amendments and a major revision in 2019, reflecting advancements in measurement technology and industrial needs. By providing standardized definitions, it enables consistent interpretation of surface characteristics between designers, manufacturers, and inspectors, which is vital for the functionality of components in fields like automotive engineering and aerospace manufacturing.

Scope and purpose

The scope of the standard encompasses the definitions of surface texture parameters obtained from profiles measured by contact stylus instruments or other equivalent methods, as detailed in companion standards like ISO 3274. Its primary purpose is to eliminate ambiguity in technical drawings, specifications, and measurement reports by providing an internationally agreed-upon set of terms. This facilitates trade, ensures product quality, and supports the implementation of geometrical dimensioning and tolerancing principles. It is applicable to surfaces produced by various processes, including turning, milling, grinding, and etching.

Key definitions and parameters

The standard meticulously defines key profile elements, separating the total profile into the roughness profile and the waviness profile through the application of specified filters. Critical amplitude parameters include Ra (arithmetical mean deviation), Rz (maximum height), and Rq (root mean square deviation). It also defines spacing parameters such as RSm (mean width of profile elements) and hybrid parameters like Rsk (skewness) and Rku (kurtosis). These parameters allow for a quantitative description of surface texture relevant to performance aspects like friction, wear, and lubrication.

Measurement principles and techniques

Measurement principles are based on extracting a two-dimensional profile from the surface, typically using a contact stylus with a defined tip radius traversing the workpiece. The standard references ISO 3274 for the nominal characteristics of such contact stylus instruments. It specifies the use of profile filters, namely the Gaussian filter, to separate the wavelength components into roughness and waviness. The evaluation process involves establishing a mean line and applying cut-off wavelengths, which are standardized in ISO 4288, to ensure comparable results regardless of the measurement equipment or laboratory.

Relation to other standards

This standard is part of an integrated system of ISO standards for surface texture. It is intrinsically linked to ISO 4288, which provides rules and procedures for applying the parameters defined here. It also relates to ISO 13565 for characterizing stratified surfaces and ISO 25178 for the areal (3D) measurement of surfaces. The definitions support broader standards on geometrical product specifications such as ISO 1101 and the ISO 1302 standard for the indication of surface texture on technical drawings.

Applications

The applications of the standard are vast and critical in precision engineering. It is used to specify and verify surface finish on components in the automotive industry for engine parts and transmissions, in the aerospace sector for turbine blades, and in the manufacture of bearings and seals. Its use ensures that surfaces meet functional requirements for fatigue strength, fluid dynamic performance, and optical properties. Compliance with the standard is routinely verified in metrology laboratories and production facilities using instruments from companies like Taylor Hobson and Mahr GmbH.

Category:ISO standards Category:Geometrical product specifications Category:Metrology