Quality
Quality System
Testing Equipment
Material Selection
Precision Casting Tolerance
Roughness Comparison

Precision Casting Tolerance

The dimensional accuracy of castings is one of the important quality indicators of castings. The dimensional tolerance standard of castings is the objective basis for measuring the dimensional accuracy of castings. GWM strictly follows the national standard GB/T6414-2017.

 

FOR INVESTMENT CASTINGS, THE FOLLOWING CORRESPONDING TOLERANCE LEVELS ARE SELECTED BASED ON THEIR MAXIMUM NOMINAL DIMENSIONS:

1. When the maximum nominal size is ≤100, choose DCTG4~DCTG6 grades;

2. If 100＜maximum nominal size≤400, choose DCTG4~DCTG8 level;

3. When the maximum nominal size is >400, choose DCTG4~DCTG9 levels.

 

CASTING DIMENSIONAL TOLERANCE (DCTG)

 

Nominal size Dimensional tolerance level (DCTG) of castings and corresponding linear dimensional tolerance values
From To DCTG1 DCTG2 DCTG3 DCTG4 DCTG5 DCTG6 DCTG7 DCTG8 DCTG9
- 10 0.09 0.13 0.18 0.26 0.36 0.52 0.74 1 1.5
10 16 0.1 0.14 0.2 0.28 0.38 0.54 0.78 1.1 1.6
16 25 0.11 0.15 0.22 0.3 0.42 0.58 0.82 1.2 1.7
25 40 0.12 0.17 0.24 0.32 0.46 0.64 0.9 1.3 1.8
40 63 0.13 0.18 0.26 0.36 0.5 0.7 1 1.4 2
63 100 0.14 0.2 0.28 0.4 0.56 0.78 1.1 1.6 2.2
100 160 0.15 0.22 0.3 0.44 0.62 0.88 1.2 1.8 2.5
160 250 - 0.24 0.34 0.5 0.7 1 1.4 2 2.8
250 400 - - 0.4 0.56 0.78 1.1 1.6 2.2 3.2
400 630 - - - 0.64 0.9 1.2 1.8 2.6 3.6
630 1000 - - - 0.72 1 1.4 2 2.8 4

 

CASTING STRAIGHTNESS TOLERANCE

 

Nominal size Geometric tolerance level (DCTG) of castings and corresponding straightness tolerances
From To DCTG2 DCTG3 DCTG4 DCTG5 DCTG6 DCTG7 DCTG8
- 10 0.08 0.12 0.18 0.27 0.4 0.6 0.9
10 30 0.12 0.18 0.27 0.4 0.6 0.9 1.4
30 100 0.18 0.27 0.4 0.6 0.9 1.4 2
100 300 0.27 0.4 0.6 0.9 1.4 2 3
300 1000 0.4 0.6 0.9 1.4 2 3 4.5
1000 3000 - - - 3 2 6 9
3000 6000 - - - 6 8 12 18
6000 10000 - - - 12 16 24 36

 

CASTING FLATNESS TOLERANCE

 

Nominal size Geometric tolerance level (DCTG) of castings and corresponding straightness tolerances
From To DCTG2 DCTG3 DCTG4 DCTG5 DCTG6 DCTG7 DCTG8
- 10 0.12 0.18 0.27 0.4 0.6 0.9 1.4
10 30 0.18 0.27 0.4 0.6 0.9 1.4 2
30 100 0.27 0.4 0.6 0.9 1.4 2 3
100 300 0.4 0.6 0.9 1.4 2 3 4.5
300 1000 0.6 0.9 1.4 2 3 4.5 7
1000 3000 - - - 4 6 9 14
3000 6000 - - - 8 12 18 28
6000 10000 - - - 16 24 32 56

 

CASTING ROUNDNESS, PARALLELISM, PERPENDICULARITY AND SYMMETRY TOLERANCES

  

Nominal size Geometric tolerance level (DCTG) of castings and corresponding straightness tolerances
From To DCTG2 DCTG3 DCTG4 DCTG5 DCTG6 DCTG7 DCTG8
- 10 0.18 0.27 0.4 0.6 0.9 1.4 2
10 30 0.27 0.4 0.6 0.9 1.4 2 3
30 100 0.4 0.6 0.9 1.4 2 3 4.5
100 300 0.6 0.9 1.4 2 3 4.5 7
300 1000 0.9 1.4 2 3 4.5 7 10
1000 3000 - - - 6 9 14 20
3000 6000 - - - 12 18 28 40
6000 10000 - - - 24 36 56 80

 

CASTING COAXIALITY TOLERANCE

 

Nominal size Geometric tolerance level (DCTG) of castings and corresponding straightness tolerances
From To DCTG2 DCTG3 DCTG4 DCTG5 DCTG6 DCTG7 DCTG8
- 10 0.27 0.4 0.6 0.9 1.4 2 3
10 30 0.4 0.6 0.9 1.4 2 3 4.5
30 100 0.6 0.9 1.4 2 3 4.5 7
100 300 0.9 1.4 2 3 4.5 7 10
300 1000 1.4 2 3 4.5 7 10 15
1000 3000 - - - 9 14 20 30
3000 6000 - - - 18 28 40 60
6000 10000 - - - 36 56 80 120