HEHUA machinery technology , LTD is a CNC machining and Sheet metal fabrication service, shanghai based factory in line with international standard, such as general tolerance ISO 2768 ISO9001 or JIS B 0405. Please refer to the ISO 2768/JIS B 0405 tables below in details.

Table 1 – Linear Dimensions

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

* For nominal size below 0.5mm, the deviation shall be indicated adjacent to the relevant nominal size(s).

Table 2 – External Radii and Chamfer Heights

Permissible deviations in mm for nominal size in mm	Tolerance class designation (description)
	f (fine)	m (medium)	c (coarse)	v (very coarse)
0.5* to 3	±0.2		±0.4
above 3 to 6	±0.5		±1.0
above 6	±1.0		±2.0

Table 3 – Angular Dimensions

Permissible deviations in mm for nominal size in mm	Tolerance class designation (description)
Permissible deviations in mm for nominal size in mm	f (fine)	m (medium)	c (coarse)	v (very coarse)
0 to 10	±1º		±1º30’	±3º
above 10 to 50	±30’		±1º	±2º
above 50 to 120	±20’		±30’	±1º
above 120 to 400	±10’		±15’	±30’
above 400	±5’		±10’	±20’

General Tolerances ISO 9001/IATF16949 /EN15085

GENERAL TOLERANCES FOR FORM AND POSITION

There are several common requirements for CNC machining services, such like straightness, flatness, perpendicularity, symmetry, run-out, and etc. A machined part may distort, tilt due to various situations:

Raw material stiffness
Raw material internal stress
Poor machining process
The CNC machine is out of alignment

Therefore, we will have to inspect the machined parts based on ISO 2768-2/JIS B 0419 below.

Table 1 – Straightness and Flatness

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

Table 2 – Perpendicularity

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

Table 3 – Symmetry

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

Table 4 – Run Out

Ranges of nominal lengths in mm	Tolerance class
	H	K	L
	0.1	0.2	0.5