ISO 4287 is the international standard that defines surface texture parameters and terminology used to describe the roughness of a surface. It provides a common language for specifying, measuring, and interpreting surface finish on technical drawings and inspection reports.
ISO 4287 is a technical product standard, widely used in machining, manufacturing, metrology, and quality control.
What is ISO 4287?
ISO 4287 is published by the International Organization for Standardization. It defines the parameters used to characterise surface roughness profiles, based on measurements taken along a defined evaluation length.
The standard does not prescribe how rough a surface should be; it defines how surface texture is described and reported.
What does ISO 4287 cover?
ISO 4287 specifies:
- Surface texture terminology
- Profile-based roughness parameters
- Mathematical definitions of roughness values
- How parameters are expressed and reported
It applies to surfaces produced by machining, grinding, polishing, casting, forming, and other manufacturing processes.
Surface texture explained
Surface texture refers to the fine irregularities on a surface after form and waviness have been removed. It affects:
- Friction and wear
- Sealing performance
- Fatigue strength
- Lubrication retention
- Appearance and feel
ISO 4287 focuses on roughness, which is one component of overall surface texture.
Common ISO 4287 roughness parameters
ISO 4287 defines many parameters. The most commonly used include:
Ra – Arithmetical mean roughness
The average deviation of the roughness profile from the mean line.
Ra is widely used but does not describe peak or valley shape.
Rz – Maximum height of profile
The average difference between the highest peak and lowest valley within sampling lengths.
Rz provides more sensitivity to surface extremes than Ra.
Rq – Root mean square roughness
The square root of the mean of the squared deviations.
More sensitive to peaks and valleys than Ra.
Rt – Total height of profile
The vertical distance between the highest peak and lowest valley over the evaluation length.
Rp / Rv – Maximum peak height / maximum valley depth
Used where peak control or valley depth is critical, such as sealing surfaces.
Why ISO 4287 is important
Using ISO 4287 helps organisations:
- Specify surface finish unambiguously
- Avoid disputes between design, manufacturing, and inspection
- Select appropriate manufacturing processes
- Control functional performance and quality
- Ensure consistency across suppliers and regions
Clear surface specification is as important as dimensional tolerancing.
ISO 4287 and surface texture symbols
ISO 4287 works alongside ISO 1302, which defines how surface texture requirements are shown on technical drawings.
ISO 4287 defines what the parameters mean; ISO 1302 defines how they are indicated on drawings.
Measurement of surface roughness
Surface roughness values defined in ISO 4287 are typically measured using:
- Contact stylus profilometers
- Non-contact optical measurement systems
Measurement conditions (cut-off length, evaluation length, filter type) must be defined correctly to ensure valid results.
Who is ISO 4287 for?
ISO 4287 is widely used by:
- Mechanical and manufacturing engineers
- CAD designers and draughtspersons
- Machinists and production teams
- Metrology and quality inspection staff
- Toolmakers and component suppliers
It is essential in industries where surface performance is critical.
ISO 4287 vs related surface standards
| Standard | Purpose |
|---|---|
| ISO 4287 | Defines roughness parameters |
| ISO 4288 | Rules for surface texture assessment |
| ISO 1302 | Surface texture symbols on drawings |
| ISO 25178 | Areal (3D) surface texture |
ISO 4287 focuses on profile (2D) roughness, not 3D surface texture.
Is ISO 4287 certifiable?
No. ISO 4287 cannot be certified.
It is a technical specification used to define and measure surface roughness. Parts are inspected against ISO 4287 parameters, but organisations are not certified to it.
Common misunderstandings about ISO 4287
- “Ra alone defines surface quality” – it often does not
- “Lower roughness is always better” – function dictates requirements
- “Measurement method does not matter” – it does
- “ISO 4287 defines acceptable limits” – it defines parameters, not limits
Correct parameter selection is critical for functional performance.
How ISO 4287 fits with other standards
ISO 4287 is commonly used alongside:
- ISO 4288 (surface texture assessment rules)
- ISO 1302 (drawing indications)
- ISO 2768 (general tolerances)
- ISO 286 (limits and fits)
- ISO 9001 (quality management systems)
Together, these standards support precise, functional product specification.
Next steps
If you are specifying or inspecting surface texture:
- Identify which surface functions are critical
- Select appropriate ISO 4287 parameters (not just Ra)
- Define measurement conditions clearly
- Indicate requirements correctly on drawings
- Align inspection methods with specification
ISOcertified.net provides guidance on ISO product and engineering standards, including ISO 4287, how to select appropriate surface roughness parameters, and how surface texture standards support reliable, high-quality manufacturing.