For the tolerances you have not specifically marked, for different processing methods, Leanplans will carry out production and processing in accordance with the tolerances described in the following text.

一、CNC Machining

Table 1.1 Numerical values of limit deviations for linear dimensions （mm）（GB/T 1804-2000）

The limit deviation of angular dimensions is selected as grade M by default for implementation:

Table 1.2 Numerical values of limit deviations for angular dimensions （mm）（GB/T 1804-2000）

The limit deviation of fillet radius and chamfer height dimensions is selected as grade M by default for implementation:

Table 1.3 Numerical values of limit deviations for fillet radius and chamfer height dimensions（mm）（GB/T 1804-2000）

The standard tolerance of processing accuracy is selected as grade T12 by default:

Table 1.4 GB/T 1804-2000 IT4-TI18 Tolerance data

The unnoted tolerance of straightness and flatness is selected as grade K by default for implementation:

Table 1.5 Unnoted tolerance values of straightness and flatness （mm）（GB/T1184-1996）

The unnoted tolerance of perpendicularity is selected as grade K by default for implementation: 

Table 1.6 Unnoted tolerance values of perpendicularity（mm）（GB/T1184-1996）

The unnoted tolerance of circular runout is selected as grade K by default for implementation:

Table 1.7 Unnoted tolerance values of circular runout（mm）（GB/T1184-1996）

The unnoted tolerance of concentricity and symmetry is implemented by default as per Table 1.8:

Table 1.8 Unnoted Tolerance of Concentricity and Symmetry（mm）(GB/T 1184-1996)

The unnoted tolerance of symmetry of keyway is implemented by default as per Table 1.9:

Table 1.9 Unnoted Tolerance of Symmetry of Keyway（mm）(GB/T 1184-1996)

The unnoted positional tolerance of screw holes and through holes for bolts is implemented by default as per Table 1.10:

Table 1.10 Unnoted Positional Tolerance of Screw Holes and Through Holes for Bolts（mm）(GB/T 1184-1996)

If surface roughness is not specified, the default is to follow Table 1.11:

Table 1.11 Unnoted Surface roughness

No tolerances are noted for linear dimensions and shape positions of welded parts, and the default is to follow Table 1.12:

Tbale 1.12 Unnoted tolerances for linear dimensions and geometrical tolerances of welded components （mm）(JB/T 5000.3-1998)

The unnoted tolerance of the angle of welded components is implemented by default as per Table 1.13: 

Table 1.13 Unnoted Tolerance of Angles of Welded Components（mm）(JB/T 5000.3-1998)

二、Sheet metal

Refer to international standards: ISO 2768, national standards: GB/T 1184-1996, GB/T 1804-2000. And the data provided by existing production suppliers (that is, the conventional accuracy that can be achieved by processing), formulate the unnoted tolerance standard for the processing accuracy of sheet metal parts, and stipulate the tolerance grade and limit deviation values of the general tolerance of the tolerance dimensions that are not noted.

Table 2.1 Limit deviation values of unnoted linear dimensions （mm）

Note: All clearance dimensions are subject to positive tolerances; the external dimensions are subject to negative tolerances.

Table 2.2 Limit deviation values of unnoted fillet radius and chamfer height dimensions（mm）

Note: All hole dimensions are subject to positive tolerances.

Table 2.3 Limit deviation values of unnoted angular dimensions（mm）

Table 2.4 Limit deviation values of unnoted center distance dimensions of holes（mm）

Table 2.5 Unnoted Tolerance Values of Straightness and Flatness（mm）

Table 2.6 Unnoted Tolerance Values of Parallelism（mm）

Table 2.7 Tolerance Requirements for Basic Material Thickness（mm）

Table 2.8 Tolerance of Angle Steel （mm）

Table 2.9 Tolerance of Square Tube Materials （mm）

三、 3D Printing

3D printing is implemented by default as per Table 4.1:

Table 3.1 Dimensions and Tolerances of 3D Printing （mm）