Legacy symbols: ISO 1302:2002 context
In the Mitutoyo legacy-symbol guide, a bar added to the basic symbol requires material removal; a circle prohibits material removal. Do not read these as “milling required” or “roughness not important”.
Keep the fields separate
Record the parameter and value, manufacturing method if specified, machining allowance and lay direction. The = and perpendicular lay descriptions are relative to the view/projection in that guide; X is crossed, M is multidirectional, C concentric and R radial.
New and old drawings
ISO 21920-1:2021 covers current profile-texture indication in the public catalogue. A drawing referring to ISO 1302 remains a version-specific reading task. A bare number, parentheses or a familiar-looking symbol is not enough to invent the parameter, acceptance rule or filter setting.
Continue your task
Sources and review scope
Reviewed 23 October 2026. Arithmetic examples are labelled separately from source-table facts and standard scope.
Mitutoyo Surface Roughness Measurement
PDF pp. 6–7: drawing symbols under DIN EN ISO 1302:2002. Legacy explanation, not the full ISO 21920 rules.
Open the original source ↗ISO 21920-1:2021
Public scope and lifecycle for profile-texture indication; predecessor ISO 1302:2002 withdrawn. Full standard not reviewed.
Open the original source ↗