This standard specifies the general tolerances and selection rules for sheet metal parts and structures. This standard applies to the general tolerances for sheet metal parts and structures in electrical equipment and equipment structures. JB/T 6753.1-1993 Electrical equipment and equipment component tolerances Sheet metal parts and structures General tolerances and selection rules JB/T6753.1-1993 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
JB/T 6753.1 -1993
Tolerances of Equipment Components of Electrical Equipment
General Tolerances and Selection Rules for Sheet Metal Parts and Structures, Issued on August 21, 1993
Ministry of Machinery Industry of the People's Republic of China
Implementation on October 1, 1993
Mechanical Industry Standard of the People's Republic of China
Tolerances of Equipment Components of Electrical Equipment
General Tolerances and Selection Rules for Sheet Metal Parts and Structures Subject Content and Scope of Application
This standard specifies the general tolerances and selection rules for sheet metal parts and structures. This standard applies to the general tolerances for the selection of sheet metal parts and structures in the equipment structure of electrical equipment. 2 Terminology
2.1 Equipment structure
JB/T 6753.1-1993
Mechanical structure including housings and mounting parts of electrical, electronic and electromechanical systems. It ensures the mutual adaptability between mechanical parts, electrical connections, and electrical and electronic components.
2.2 Sheet metal parts
In the equipment structure of electrical equipment, metal sheet materials are used. The parts processed by cold working and stamping are sheet metal parts. Such as doors, side panels, beam bracket mounting plates, etc.
2.3 General tolerances
Under typical conventional process conditions, the dimensional tolerances and form and position tolerances that can be guaranteed are called general tolerances. This type of tolerance is generally not separately noted on the drawing.
General tolerances for linear dimensions
Tolerance grades
The general tolerances for linear dimensions are divided into seven grades: A, B, C, D, E, F, and G. The tolerance values ​​are shown in Table 1.
Dimension segment
>30~120
>120~400
>400~1000
1000~2000
2000~4000
3.2 Method for selecting general tolerances of linear dimensions B
When selecting the general tolerances of linear dimensions specified in Table 1, the limit deviation values ​​can be selected according to the bidirectional symmetrical deviation or the unidirectional deviation.
For example, tolerance value is 0.2, limit deviation can be taken as ±0.1, -: or +*, approved by the Ministry of Machinery Industry on August 21, 1993, implemented on October 1, 1993, general tolerance of structural verticality, JB/T6753.1-1993, the general tolerance of structural verticality is divided into three levels: A, B and C, and the tolerance values ​​are shown in Table 2. Table 2 Size segmentation >400~1000 >1000~1600 >1600~2500 >2500~4000 Basic size is the short side size General tolerance of straightness and flatness is under consideration.
General tolerances for perpendicularity and parallelism
Under consideration.
7General tolerances for hole position
General tolerances for hole position shall be taken according to the bidirectional symmetry in Table 1 as their limit deviations. Selection of general tolerances
1When selecting the general tolerances specified in this standard, they may be specified in the corresponding technical documents or standards, or directly marked in the product drawings. 8.1
When applying this standard, the standards for structures and their components may select tolerance values ​​from Table 1 according to the characteristics of the process elements, and then, combined with the selection characteristics of their respective standards, 8.2
, allow the tolerance grades and tolerance series to be re-arranged in the order of A, B, C, D, E, F, and G. 8.3It is allowed to directly reference the same tolerance grade or different tolerance grades of this standard in technical documents or drawings. 9 Marking
When all the same tolerance grades are used, the element name, standard code and tolerance grade code shall be indicated in the technical documents or drawings. 9.1
General tolerance
JB/T6753.1-A
(±, or +)
Value method
Tolerance grade codebZxz.net
Standard code
Element name
9.2 When different tolerance grades are used, the element name, standard code and tolerance grade code shall be indicated in the technical documents or drawings according to the provisions of 9.1.
For example: General tolerance of linear dimensions JB/T6753.1A (±) General tolerance of verticality JB/T6753.1-B2
JB/T6753.1-1993
When necessary, the limit deviation value of the corresponding tolerance grade of this standard can be directly indicated in the drawing. 9.3
For example: directly marked as 800-1.5 in the drawing. Additional remarks:
This standard is proposed and managed by Beijing Institute of Electrical Engineering Comprehensive Technology and Economy. This standard is drafted by Tianjin Electric Drive Design Institute, Xuchang Relay Institute, Shenyang Low Voltage Switch Factory, and Shanghai Huatong Switch Factory. Shanghai Electric Complete Set Factory, Kunming Switch Factory, Beijing Second Switch Factory, and Guangzhou Nanyang Electric Factory participated in the drafting. The main drafters of this standard are Guo Xiaohu, Tian Pu, Cui Guochang, Zhou Guixin, and Wang Aimin. 3
661 - 1E9 /
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