DESHENGRUI MACHINERY

Hotline
Mechanical Knowledge

ISO2768 tolerance quick check


Table 1 – Allowable deviations for linear dimensions (excluding damaged edges)
Value is expressed in mm
Tolerance level Allowable deviation of nominal size
name description 0.51) ~ 3 >3 ~ 6 >6 ~ 30 >30 ~ 120 >120 ~ 400 >400 ~ 1000 >1000 ~ 2000 >2000 ~ 4000
f Precision level ±0.05 ±0.05 ±0.1 ±0.15 ±0.2 ±0.3 ±0.5 -
m Medium level ±0.1 ±0.1 ±0.2 ±0.3 ±0.5 ±0.8 ±1.2 ±2
c Rough grade ±0.2 ±0.3 ±0.5 ±0.8 ±1.2 ±2 ±3 ±4
v The coarsest level - ±0.5 ±1 ±1.5 ±2.5 ±4 ±6 ±8
1) For nominal dimensions below 0.5mm, the deviation shall be marked after the nominal size.










Table 2 – Permissible deviations from the linear dimensions of the damaged edge (rounding radius and chamfer height)

Value is expressed in mm

Tolerance level Allowable deviation of nominal size

name description 0.5 1) ~ 3 > 3 ~ 6 > 6

f Precision level ±0.2 ±0.5 ±1

m Medium level

c Rough grade ±0.4 ±1 ±2

v The coarsest level

1) For nominal dimensions below 0.5mm, the deviation shall be marked after the nominal size.











Table 3 - Allowable deviations for angular dimensions


Value is expressed in mm


Tolerance level Angle deviation of the short side of the allowed angle according to the length (mm)


name description ≤10 >10 ~ 50 > 50 ~ 120 >120 ~ 400 > 400


f Precision level ±1 ̊ ±0 ̊30 ́ ±0 ̊20 ́ ±0 ̊10 ́ ±0 ̊5 ́


m Medium level


c Rough grade ±1 ̊30 ́ ±1 ̊ ±0 ̊30 ́ ±0 ̊15 ́ ±0 ̊10 ́


v The coarsest level ±3 ̊ ±2 ̊ ±1 ̊ ±0 ̊30 ́ ±0 ̊20 ́












Table 1 – General tolerances for flatness and flatness
Table 4 – General tolerances for circumferential runout
Value is expressed in mm
Value is expressed in mm
Tolerance 
level
Flat tolerances for flatness and flatness of the nominal length range
Tolerance level Circumferential runout tolerance
≤10 >10-30 >30-100 >100-300 >300-1000 >1000-3000
H 0.1
H 0.02 0.06 0.1 0.2 0.3 0.4
K 0.2
K 0.05 0.1 0.2 0.4 0.6 0.8
L 0.5
L 0.1 0.2 0.4 0.8 1.2 1.6








Table 2 – General tolerances for straightness Table 3 – Symmetry General Tolerance
Value is expressed in mm Value is expressed in mm
Tolerance 
level
Straightness tolerance of the short length of the nominal length Tolerance 
level
Straightness tolerance of the short length of the nominal length
≤100 >100-300 >300-1000 >1000-3000 ≤100 >100-300 >300-1000 >1000-3000
H 0.2 0.3 0.4 0.5 H 0.5
K 0.4 0.6 0.8 1 K 0.6 0.8 1
L 0.6 1 1.5 2 L 0.6 1 1.5 2

PREVIOUS:CNC machining, steel forging, casting, and surface hardening
NEXT:Casting Process,sand casting, investment casting, die casting