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CNC Machining Tolerances

General Tolerances to DIN ISO 2768

Our usual metals tolerance for CNC machining is DIN-2768-1-fine, and for the usual plastics tolerance is DIN-2768-1-medium. Of course, the parts have different shapes and different processes, the standard tolerances are different. Therefore, our project engineers will confirm every detail of your project. We will try our best to meet your expected tolerances. If there are special circumstances that can't be met, we will give modification suggestions and confirm with you.

The below latest DIN standard sheet version applies is suitable for all parts made to DIN standards.
Our usual metals tolerance for CNC machining is DIN-2768-1-fine, and for the usual plastics tolerance is DIN-2768-1-medium.

GENERAL TOLERANCES FOR LINEAR AND ANGULAR DIMENSIONS (DIN ISO 2768 T1)

LINEAR DIMENSIONS

Permissible deviations in mm for ranges in nominal lengths	f (fine)	Tolerance class designation (description)		v (very coarse)
Permissible deviations in mm for ranges in nominal lengths	f (fine)	m (medium)	c (coarse)	v (very coarse)
0.5 up to 3	±0.05	±0.1	±0.2	-
over 3 up to 6	±0.05	±0.1	±0.3	±0.5
over 6 up to 30	±0.1	±0.2	±0.5	±1.0
over 30 up to 120	±0.15	±0.3	±0.8	±1.5
over 120 up to 400	±0.2	±0.5	±1.2	±2.5
over 400 up to 1000	±0.3	±0.8	±2.0	±4.0
over 1000 up to 2000	±0.5	±1.2	±3.0	±6.0
over 2000 up to 4000	-	±2.0	±4.0	±8.0

EXTERNAL RADIUS AND CHAMFER HEIGHTS

Permissible deviations in mm for ranges in nominal lengths	f (fine)	Tolerance class designation (description)		v (very coarse)
Permissible deviations in mm for ranges in nominal lengths	f (fine)	m (middle)	c (coarse)	v (very coarse)
0.5 up to 3	±0.2	±0.2	±0.4	±0.4
over 3 up to 6	±0.5	±0.5	±1.0	±1.0
over 6	±1.0	±1.0	±2.0	±2.0

ANGULAR DIMENSIONS

Permissible deviations in degrees and minutes for ranges in nominal lengths	f (fine)	Tolerance class designation (description)		v (very coarse)
	f (fine)	m (middle)	c (coarse)	v (very coarse)
up to 10	±1º	±1º	±1º30'	±3º
over 10 up to 50	±0º30'	±0º30'	±1º	±2º
over 50 up to 120	±0º20'	±0º20'	±0º30'	±1º
over 120 up to 400	±0º10'	±0º10'	±0º15'	±0º30'
over 400	±0º5'	±0º5'	±0º10'	±0º20'

GENERAL TOLERANCES FOR FORM AND POSITION (DIN ISO 2768 T2)

STRAIGHTNESS AND FLATNESS

Ranges in nominal lengths in mm	Tolerance class
Ranges in nominal lengths in mm	H	K	L
up to 10	0.02	0.05	0.1
over 10 up to 30	0.05	0.1	0.2
over 30 up to 100	0.1	0.2	0.4
over 100 up to 300	0.2	0.4	0.8
over 300 up to 1000	0.3	0.6	1.2
over 1000 up to 3000	0.4	0.8	1.6

PERPENDICULARITY

Ranges in nominal lengths in mm	Tolerance class
Ranges in nominal lengths in mm	H	K	L
up to 100	0.2	0.4	0.6
over 100 up to 300	0.3	0.6	1
over 300 up to 1000	0.4	0.8	1.5
over 1000 up to 3000	0.5	0.8	2

SYMMETRY

Ranges in nominal lengths in mm	Tolerance class
Ranges in nominal lengths in mm	H	K	L
up to 100	0.5	0.6	0.6
over 100 up to 300	0.5	0.6	1
over 300 up to 1000	0.5	0.8	1.5
over 1000 up to 3000	0.5	1	2

RUN-OUT

Tolerance class
H	K	L
0.1	0.2	0.5