	Unit & Tolerance

Normal tolerance for working dimensions

General

Tolerance level selection must consider working precision normally achieved in individual factories. When smaller tolerance is required for each feature, or when larger tolerance is permissible and is more economical, it is recommended to individually indicate such tolerance following its master dimension.

Normal tolerance

Length

The normal tolerance for length depends on the allowance shown in Table 1 and Table 2.

Table 1 Allowance for length excluding chamfers

(Refer to Table 2 for the roundness of edges and the chamfer dimensions of edges.)	Unit: mm

Tolerance level		Master dimension
Symbol	Level	0.5 or more ^*1 to 3 or less	More than 3 to 6 or less	More than 6 to 30 or less	More than 30 to 120 or less	More than 120 to 400 or less	More than 400 to 1000 or less	More than 1000 to 2000 or less	More than 2000 to 4000 or less
Symbol	Level	Allowance
f	Fine	±0.05	±0.05	±0.1	±0.15	±0.2	±0.3	±0.5	-
m	Midium	±0.1	±0.1	±0.2	±0.3	±0.5	±0.8	±1.2	±2
c	Coarse	±0.2	±0.3	±0.5	±0.8	±1.2	±2	±3	±4
v	Very coarse	-	±0.5	±1	±1.5	±2.5	±4	±6	±8


1.	As for the master dimension for the length of less than 0.5 mm, the allowance should be individually indicated after its master dimension.

Table 2 Allowance for length of chamfers

(The roundness of edges and the chamfer dimensions of edges)

Unit: mm

Tolerance level		Master dimension
Symbol	Level	0.5 or more ^*1 to 3 less	More than 3 to 6 or less	More than 6
		Allowance
f	Fine	±0.2	±0.5	±1
m	Midium
c	Coarse	±0.4	±1	±2
v	Very coarse


1.	As for the master dimension for the chamfer of less than 0.5 mm, the allowance should be individually indicated after its master dimension.

Angle

The normal tolerance specified in the unit of angle restricts only the typical position of lines or the segments that form the surface. It does not restrict the deviation in their shapes.
The typical position of the line obtained from the actual surface is determined by the position of the contact line of an ideal geometrical shape. The maximum interval between the contact line and the actual line must be shortened as much as possible.
The normal tolerance for angle depends on the allowance shown in Table 3.

Table 3 Allowance for angle

Tolerance level		Master dimension
Symbol	Level	10 or less	More than 10 to or 50 less	More than 50 to or 120 less	More than 120 to or 400 less	More than 400
		Allowance
f	Fine	±1º	±30'	±20'	±10'	±5'
m	Midium
c	Coarse	±130'	±1º	±30'	±15'	±10'
v	Very coarse	±3º	±2º	±1º	±30'	±20'

Normal tolerance for dimension of pressed metal

Scope

This standard specifies the normal tolerance for the dimension of pressed metal.
The phrase "pressed metal" used in this section refers to the metal sheets being stamped, bent or drawn by a press. The sheared metal sheets are not included.

Normal tolerance for dimension of stamped metal

There are three levels for the normal tolerance for dimension of stamped metal: A, B and C. Table 1 shows the allowance for each level.

Table 1 Normal tolerance for dimension of stamped metal	Unit: mm

Master dimension	Level
Master dimension	A	B	C
6 or less	±0.05	±0.1	±0.3
More than 6 to 30 or less	±0.1	±0.2	±0.5
More than 30 to 120 or less	±0.15	±0.3	±0.8
More than 120 to 400 or less	±0.2	±0.5	±1.2
More than 400 to 1000 or less	±0.3	±0.8	±2
More than 1000 to 2000 or less	±0.5	±1.2	±3


Note:	Levels A, B and C correspond to f, m and c of the tolerance levels of JIS B 0405 respectively.

Normal tolerance for dimension of bent or drawn metal

There are three levels for the normal tolerance for dimension of bent or drawn metal: A, B and C. Table 2 shows the allowance for each level.

Table 2 Normal tolerance for dimension of bent or drawn metal	Unit: mm

Master dimension	Level
Master dimension	A	B	C
6 or less	±0.1	±0.3	±0.5
More than 6 to 30 or less	±0.2	±0.5	±1
More than 30 to 120 or less	±0.3	±0.8	±1.5
More than 120 to 400 or less	±0.5	±1.2	±2.5
More than 400 to 1000 or less	±0.8	±2	±4
More than 1000 to 2000 or less	±1.2	±3	±6


Note:	Levels A, B and C correspond to m, c and v of the tolerance levels of JIS B 0405 respectively.

Normal tolerance for castings

Scope

This standard applies to sand-mold casting (excluding precision casting or equivalent casting). It specifies the normal tolerance for the length and thickness of gray cast iron and nodular graphite cast iron when molds are removed (hereinafter referred to as "normal tolerance").

Table 1 Normal tolerance for length	Unit: mm

Dimension	Material	Gray cast iron		Nodular graphite cast iron
Dimension	Level	Fine	Coarse	Fine	Coarse
120 or less		±1	±1.5	±1.5	±2
More than 120 to 250 or less		±1.5	±2	±2	±2.5
More than 250 to 400 or less		±2	±3	±2.5	±3.5
More than 400 to 800 or less		±3	±4	±4	±5
More than 800 to 1600 or less		±4	±6	±5	±7
More than 1600 to 3150 or less		-	±10	-	±10

Table 2 Normal tolerance for thickness	Unit: mm

Dimension	Material	Gray cast iron		Nodular graphite cast iron
Dimension	Level	Fine	Coarse	Fine	Coarse
10 or less		±1	±1.5	±1.2	±2
More than 10 to 18 or less		±1.5	±2	±1.5	±2.5
More than 18 to 30 or less		±2	±3	±2	±3
More than 30 to 50 or less		±2	±3.5	±2.5	±4

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Normal tolerance for working dimensions

General

Normal tolerance

Length

Table 1 Allowance for length excluding chamfers

Table 2 Allowance for length of chamfers

Angle

Table 3 Allowance for angle

Normal tolerance for dimension of pressed metal

Scope

Normal tolerance for dimension of stamped metal

Table 1 Normal tolerance for dimension of stamped metal

Normal tolerance for dimension of bent or drawn metal

Table 2 Normal tolerance for dimension of bent or drawn metal

Normal tolerance for castings

Scope

Table 1 Normal tolerance for length

Table 2 Normal tolerance for thickness