Orientation Tolerance Spec Table

Orientation Tolerance KS Specifications — 3 sizes

KS A ISO 1101

Tolerances specifying orientation accuracy relative to a datum: parallelism, perpendicularity, and angularity.

Practical Notes

Datum selection is key. Set the most functionally critical surface as primary datum (A).
Perpendicularity is essential for bearing housing machining. Poor squareness drastically reduces bearing life.

Selection Guide

Controls feature orientation relative to datums: perpendicularity, parallelism, angularity. Typical examples: bearing housing squareness, mold parting surface parallelism. Datum selection is key — set the most functionally critical surface as primary datum (A).

KSOrientation Tolerance

3 sizes

Name	Type	Symbol	Datum	Definition	Application
Parallelism	Orientation Tolerance	∥	Required	/ Surface	Shaft , Surface
Perpendicularity	Orientation Tolerance	⟂	Required	Angle / Surface	Surface, Shaft, Surface
Angularity	Orientation Tolerance	∠	Required	Angle	Surface, ,

Key Features

Datum (reference feature) mandatory; controls angularity, perpendicularity, and parallelism relative to datum
Three types: perpendicularity, parallelism, angularity; 2D (line) or 3D (surface) tolerance zone selectable
MMC (Maximum Material Condition) / LMC (Least Material Condition) modifiers applicable

Key Applications

Bearing housing perpendicularity, mold parting surface parallelism, V-block angularity, gear shaft alignment, machine column squareness

FAQ

Which is more commonly used: parallelism or perpendicularity?

Both are very common, but perpendicularity is slightly more frequent. Essential for bearing housings, mold parting surfaces, and machine assembly faces.