JB/T 2989-1999 Plate thickness micrometer

JB/T 2989-1999 This standard is a revision of JB 2989-81 "Plate Thickness Micrometer". During the revision, only the editorial modification was made according to the relevant regulations, and the main technical content was not changed. This standard specifies the type and size, technical requirements, marking and packaging of plate thickness micrometers. This standard is applicable to plate thickness micrometers with a sub-division value of 0.01mm and a measuring range of up to 25mm. This standard was first issued in 1981. JB/T 2989-1999 Plate Thickness Micrometer JB/T2989-1999 Standard download decompression password: www.bzxz.net

ICS25.060.20
Standard of the Machinery Industry of the People's Republic of China
JB/T2989-1999
Sheet metal micrometer
Published on May 20, 1999
National Bureau of Machinery Industry
Implemented on January 1, 2000
JB/T2989—1999
This standard is revised on the basis of JB2989-81 "Sheet metal micrometer". The technical content of this standard is consistent with that of JB2989-81, and it has only been re-edited according to relevant regulations. This standard replaces JB2989-81 from the date of implementation. This standard is proposed and managed by the National Technical Committee for Standardization of Measuring Tools and Instruments. The responsible drafting unit of this standard is Beijing No. 2 Measuring Tool Factory. This standard was first issued in 1981.
Standard of the Machinery Industry of the People's Republic of China
Plate Thickness Micrometer
Shcet Metal Micrometer
This standard specifies the type and size, technical requirements, marking and packaging of plate thickness micrometer. JB/T2989—1999
Replaces JB298981
This standard applies to plate thickness micrometers (hereinafter referred to as micrometers) with a graduation value of 0.01mm and a measuring range of up to 25mm. 2 Definitions
This standard adopts the following definitions.
2.1 Plate Thickness Micrometer
An outside diameter micrometer with a spherical measuring surface and a flat measuring surface and a special shape of the ruler frame, suitable for measuring the thickness of plates. 3 Types and Dimensions
The types of micrometers are shown in Figures 1 and 2 (the diagrams are for illustration only and do not represent the detailed structure). Measuring bricks and screws
Approved by the State Machinery Industry Bureau on 1999-05-20
Pig parts due to fixed casing differential
Figure 11 Type plate thickness micrometer
Implementation on 2000-01-01
JB/T2989-1999
Yueju Equipment Company
Differential order
Figure 2Ⅱ Type plate thickness micrometer
3.2 The measuring range of the micrometer and the recessed depth H of the scale frame are specified in Table 1. Table 1
Measuring range
0~10,0-20,0-25
3.3The measuring end diameter of the micrometer screw should be 6.5mm or 8mm. 3.4The micrometer should have a force measuring device and a locking device to tighten the micrometer rod. 4 Technical requirements
4.1The micrometer shall not have external defects that seriously affect the appearance and performance. 4.2
The movement of the micrometer screw should be smooth, and there should be no axial movement that can be felt. Square measuring devicebzxZ.net
Rubber frame recessed depth H
40,80,150
4.3The hardness of the micrometer measuring surface should not be less than 766HV (~62HRC), and the surface roughness R value should be 0.08um. mm
4.41 The width of the scale line and the pointer tip on the micrometer scale should be 0.20-0.30mm, and the difference in scale line width should not be greater than 0.05mm
The width of the scale line on the fixed sleeve of the type III micrometer and the differential cylinder should be 0.10-0.20mm, and the difference in scale line width should not be greater than 0.05mm.
JB/T2989-1999
4.51 The pointer length of the micrometer should ensure that the pointer tip is between 30%-80% of the short scale line length, and the gap between the pointer tip and the dial surface should not be greater than 0.70mm.
The distance from the surface of the longitudinal scale line of the fixed sleeve of the type III micrometer to the edge of the cone surface of the differential cylinder should not be greater than 0.40mm. 4.6 When the micrometer is zeroed, the distance from the end face of the differential cone to the fixed sleeve scale line is allowed to be no more than 0.05mm for pressure line and no more than 0.10mm for off-line
4.7 The flatness tolerance of the micrometer measuring surface is 1.0μm for level 1 and 1.5μm for level 2 (excluding the range of 0.5mm from the edge of the measuring surface). 4.8 When the micrometer measuring surface contacts the spherical surface, its measuring force should be 6~10N. 4.9 The indication error of the micrometer, the parallelism tolerance of the two measuring surfaces, and the deformation of the scale frame when subjected to a force of 10N along the axis of the micrometer screw should not exceed the provisions of Table 2.
Indication error
Measuring range
4.10 The micrometer should be equipped with a tool for adjusting the zero position. 5 Marking and packaging
5.1 The micrometer should be marked with:
a) manufacturer's name or registered trademark;
b) graduation value and measuring range:
c) product serial number.
5.2 The nominal size should be marked on the calibration rod. 5.3 The micrometer packaging box should be marked with:
a) manufacturer's name or registered trademark:
b) product name and measuring range.
Parallelism of two measuring surfaces
Deformation of the scale frame when subjected to a force of 10N
Deepness of the scale frame H
5.4 The micrometer should be treated with rust prevention and properly packaged before packaging. The product should not be damaged during transportation due to poor packaging. 5.5 Micrometers that have been verified to meet the requirements of this standard should be accompanied by a product certificate, which should be marked with the standard number of this standard, product serial number and factory date.
Mechanical Industry Standard
Plate Thickness Micrometer
JB/T2989—1999
Published by the Machinery Standardization Research Institute of the Ministry of Machinery Industry Printed by the Machinery Standardization Research Institute of the Ministry of Machinery Industry (No. 2 Shouti South Road, Beijing: Postal Code 100044)*
1/16 Printing Sheet 1/2 Number of Words 8000
Format 880×1230
First Printing in August 1999
First Edition in August 1999
Print Quantity 1-500
Price 500 Yuan
99-426
666867
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