JB/T 5821-1991 Tolerances and fittings of common threads for lead-acid batteries

This standard specifies the tolerances and fits of common threads for lead-acid batteries. This standard applies to common threads made of hard rubber, plastic, lead and lead alloys. JB/T 5821-1991 Tolerances and fits of common threads for lead-acid batteries JB/T5821-1991 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
Tolerances and fits of common threads for lead-acid batteries Subject content and scope of application
This standard specifies the tolerances and fits of common threads for lead-acid batteries. This standard applies to common threads made of hard rubber, plastic, lead and lead alloys. Reference standards
Basic tooth profile
Ordinary thread
Ordinary thread
Ordinary thread
Basic tooth profile
Diameter and pitch series
Basic dimensions
Tolerances and fits
The basic tooth profile of the thread complies with the provisions of Chapter 1 of GB192. 3.2
The diameter and pitch series of the thread are shown in Table 1.
Nominal size
Pitch P
Nominal size
Pitch P
Basic dimensions of thread
The basic dimensions of thread are shown in Table 2.
Thread tolerance and limit deviation
JB582191
According to (GB197 1.2 and 1.3 stipulate that the basic deviation code of internal thread is H. The basic deviation code of external thread is g. Internal thread tolerance 5.1
Grade is 7, and the tolerance grade of external thread is 8, and the tolerance zone code is 7H.8g. 5.2 The tolerances of thread diameter and pitch diameter are shown in Table 3 and Table 4. 5.3
Deviation code
The deviation code conforms to the provisions of GB197, namely:
The upper deviation code of each diameter of internal thread is s, and the lower deviation code is Ei. The upper deviation code of each diameter of external thread is es, and the lower deviation code is ei. 5.4 The limit deviation is shown in Table 5.
Approved by the Ministry of Machinery and Electronics Industry on October 17, 1991 23+
1992-10- 01 Implementation
Nominal size
Pitch p
Middle diameter D or d
Minor diameter D or d
Nominal size
Pitch P
Middle diameter D or d
Minor diameter D or d
Nominal size
Pitch P
Middle diameter D or d
Minor diameter D or d
Nominal size||tt ||Pitch P
Medium diameter D or d
Minor diameter D or d
JB5821—91
12.37613.835
Internal thread minor diameter tolerance tD,bzxZ.net
Standard tolerance
Pitch P
Additional value
15.29415.835
Internal thread minor diameter tolerance
) = TD; +
Pitch P
6, 647
10. 10510, 376
18. 376|20. 701;22. (051/22. 70117.29419.83520.752
45. 40255. 42
42.58743.67050.046
Tolerance of external thread diameter tdl
Standard tolerance
Additional value
Tolerance of external thread diameter
td- · Td +6
Nominal diameter
12, 14, 15
18, 20, 22
25, 27, 30
48, 56
64, 72, 80
85, 100
Internal thread pitch diameter tolerance tD
Standard tolerance
Additional value
JB5821-91
Internal thread pitch diameter tolerance
Nominal diameter||t t||8, 10
12, 14, 15
18.20, 22
24, 27, 30
36, 42,
48, 56
64, 72.80
85,100
110, 125
Tolerance of middle diameter of external thread td
Standard tolerance
Additional value
Tolerance of middle diameter of external thread
td, -- Td,+$
Nominal diameter
12, 14, 16
18,20, 22
25, 27, 30
36, 42,
64.72, %0
110, 125
JB582191.
Internal thread tolerance zone
Pitch diameter D
Minor diameter D,
External thread tolerance zone
Pitch diameter d
Major diameter d
-0, 74
6Selection and marking of diameter and pitch
JB5821-91
6.1 The selection of thread diameter and pitch shall be within the range specified in the standard (Table 2). 6.2 The thread marking consists of the thread code and the thread tolerance zone code. This standard stipulates that the thread pitch diameter and top diameter tolerance zones are the same. When marking, only 7H or 8g is marked, and the thread code and tolerance code are separated by *\. For example: M20-7HI or M20X2-7H (internal thread). M20--8g or M20X2-8g (external thread). 6.3 This standard only stipulates that the internal and external threads are combined into 7H/8g, and the tolerance zone code is marked after the thread code. For example: M20-7H/8g or M20X2-7H/g.
Whether it is a thread or a combination of internal and external threads, the words "thread tolerance shall be in accordance with JB5821--91" must be indicated in the technical requirements column of the drawing.
F scale with a graduation value of 0.01mm (including internal diameter micrometer). Vernier caliper (referred to as caliper) with a graduation value of 0.02mm. 60° thread template.
Needle (thread) for measuring the pitch diameter of the thread.
7.2 Measurement
7.2.1 Measurement of pitch Measure
Use a 60\ thread template, and the thread is completely contained by the template within the thread screw-in length. 7.2.2 Measurement of thread top diameter
First use a caliper to measure, and then use a micrometer if the number is close to the limit deviation. When measuring, measure three locations in the radial direction and calculate the arithmetic mean. Additional remarks:
The standard was proposed and managed by Shenyang Battery Research Institute. This standard was drafted by Shenyang Battery Research Institute. The main drafters of this standard are: Wu Shennan and He Cilong. 238
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