Surface Texture - Contour Measuring Instruments - Explanation of Surface Characteristics & Standards

Oct 29, 2026

Surface texture measurement covers definitions, instruments, and the ISO-based standards used to characterize roughness and waviness. The content explains profile tracing with stylus systems and phase-correct filters, introduces roughness and waviness parameters (including P-, W-, and R-parameter concepts), and details selection of cutoff wavelengths and stylus tip geometry. It also provides step-by-step evaluation procedures, comparison rules using 16% or max limits, and definitions of sampling and evaluation lengths for both nonperiodic and periodic profiles.

LanguageEnglish

CategoryTechnology

FormatPDF

Pages8

Reading Time20 min

AccessFree to download

Definition of Surface Texture and Stylus Instruments

Profile by Stylus and Phase-Correct Filter

Selection of Cutoff Wavelength and Stylus Tip Geometry

Evaluation Procedure of Roughness

16% Rule and Max Rule

Sampling Length and Evaluation Length

Indication of Surface Texture (ISO 1302)

Surface Lay and Orientation Parameters

Basic Surface Texture Parameters and Curves

Surface Texture ・ Contour Measuring Instruments Explanation of Surface Characteristics ・ Standards 〉〉〉・ Surface Texture Contour Measuring Instruments 230 Definition of Surface texture and Stylus instrument Profile by Stylus and phase correct filter ISO4287: ’97 and ISO3274: ’96 λf profile filter Waviness profile W (Filtered center line waviness profile) W-parameter |
deformation | Phase correct filter 50% transmission at cutoff No phase shift / low distortion

Roughness profile RR-parameter
| | | --- | --- | --- | | | | | | | | | Roughness profile Waviness profile Measure perpendicular to lay Real surface Traced profile perpendicular to real surface • Stylus • Noise Total profile Primary profile P P-parameter Form deviation profile =Mean line for roughness profile =Waviness profile on old DIN & JIS Stylus tip geometry θ = 60° (or 90°) cone rtip = 2μm (or 5, 10μm) 100% 50% 0 Cutoff (Wavelength) λc λs λc λf Wavelength λ Selection of λc & Stylus Tip rtip | λc (mm) | | λc/λs | rtip (μm) | | --- | --- | --- | --- | | 0.08 | 2.5 | 30 | 2 | | 0.25 | | 100 | | | 0.8 | | 300 | 2 (5 at RZ > 3μm) | | 2.5 | 8 | | 5 or 2 | | 8 | 25 | | 10, 5 or 2 | Transmission Evaluation procedure of roughness ISO4288: ’96 1. View the surface and decide whether profile is periodic or nonperiodic. 2. When the tolerance limit is specified, use the table shown on the left for condition. 3. When the tolerance limit is not specified. 3.1 Estimate roughness and measure it in corresponding condition in the table. 3.2 Change condition according with above result and measure it again. 3.3 Repeat “3.2” if the result does not reached the condition. 3.4 When the result reaches the condition, it will be the final value. Check it in shorter sampling length at non-periodic and change it if it meets. 4. Compare the result toward tolerance limit in accordance with following rule, |
Upper limit-the 16% rule (Default) | | --- | | Measure on the most critical surface. If not more than 16% of all value based on sampling length are exceed the limit, surface is acceptable.
-The first value does not exceed 70% of the limit.
-The first three values do not exceed the limit.
-Not more than one of the first six value exceed the limit.
-Not more than two of the first twelve value exceed the limit. or when μ+σ does not exceed the limit, the result is acceptable. | |
Lower limit-the 16% rule (shown as L) | | --- | | Measure the surface that can be expected the lowest roughness. If not more than 16% of all sampling length are less than the limit, or when μ-σ is not less than the limit, the result is acceptable. | |
Max value-the max rule (when “max”suffix is added) | | --- | | The value is acceptable when none of value in entire surface is over the limit. | and Evaluation length Sampling length ISO4287: ’97 Primary profile P line Mean |

Top of profile peak
Profile peak
Roughness profile R
Mean line
Profile valley
Sampling length = Cutoff λc
Rr
Rr Rr
Bottom of profile valley
Rr Rr
Evaluation length Rn＝ n×Rr (n: Default 5)

Profile element width Xs

| | | | --- | --- | --- | |
Pre travel Rp (λc/2) | Tracing length Lt＝ Lp＋Ln＋Lp |
Post travel Rp (λc/2)
| Indication of surface texture ISO 1302: ’02 Note.: Default item (red) is not indicated. Additional item (blue) is indicated if necessary. Machining allowance (mm) Surface lay and orientation =, ⊥, X, M, C, R, P The second surface parameter and condition | Parameter | | | --- | --- | | Profile | Type | No. of S. length n (Default 5) Comparison rule 16% or max Value limit (μm) U “2RC” 0.008–2.5/Rz3max 12.3 Measuring condition: R-parameter ISO4288: ’96 | Non-periodic profile | | | | Periodic profile
or RSm | | Measuring Condition | | | --- | --- | --- | --- | -

FAQs

How are cutoff wavelength and stylus tip geometry selected for surface texture measurement?

Cutoff wavelength (λc) is chosen together with stylus tip radius (rtip) and the corresponding measurement conditions. Tables relate λc/λs and rtip values, and examples specify typical tip geometries like θ = 60° or 90° with rtip options such as 2 μm, 5 μm, or 10 μm.

What are the main steps in evaluating roughness according to the procedure?

The evaluation procedure includes inspecting whether the profile is periodic or nonperiodic, applying table conditions when tolerance limits are specified, estimating and re-measuring under corresponding conditions when they are not specified, repeating adjustments until the condition is met, and then validating with a shorter sampling length for nonperiodic cases.

How do the 16% rule and max rule determine whether a surface is acceptable?

Under the upper limit 16% rule, the surface is acceptable if no more than 16% of all sampled values exceed the limit and additional constraints for the first values are met. Under the max rule, the surface is acceptable only if none of the values over the entire surface exceed the limit.

Oct 29, 2026

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