JB/T 7980-1999 This standard is a revision of JB/T 7980-95 "Radius Template". During the revision, editorial changes were made according to relevant regulations, and the technical content remained unchanged. This standard specifies the type and size, technical requirements, marking and packaging of radius templates. This standard is applicable to the inspection of convex and concave, arc radius from 1 to 25mm radius templates. This standard was first issued in 1977 as JB 2211-77, revised to GB9054-88 in April 1988, and adjusted to JB/T 7980-95 in April 1996. JB/T 7980-1999 Radius Template JB/T7980-1999 Standard Download Decompression Password: www.bzxz.net

ICS 25.060.20
Machinery Industry Standard of the People's Republic of China
JB/T7980-1999
Radius template
Radius template
Published on May 20, 1999
National Bureau of Machinery Industry
Implemented on January 1, 2000
JB/T7980-1999wwW.bzxz.Net
This standard is revised on the basis of JB/T7980--95 "Radius template". The technical content of this standard is consistent with that of JB/T7980-95, and it has only been re-edited according to relevant regulations. Appendix A of this standard is the appendix of the standard.
This standard replaces JB/T7980-95 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: Shanghai Xinyu Instrument Factory. This standard was first issued in 1977 as JB2211-77, revised to GB9054-88 in April 1988, and adjusted to JB/T7980-95 in April 1996.
Mechanical Industry Standard of the People's Republic of China
Radius template
Radius template
This standard specifies the type and size, technical requirements, marking and packaging of radius templates. This standard is applicable to the inspection of convex and concave radius templates with arc radius ranging from 1 to 25mm. Definition
This standard adopts the following definitions.
2.1 Radius template
A thin plate with a set of accurate inner and outer arc radius dimensions, used to measure the arc radius. 3 Type and size
3.1 The set radius template consists of a convex template and a concave template, and its type is shown in Figure 1. Product shape sample
Screw or nail
Protective plate
JB/T7980-1999
JB/T7980-95
Concave sample
3.2 Grouped radius samples are divided into three groups according to the size range of their radius: 1, 2, and 3. The size series of sample thickness, width, and radius are shown in Table 1.
Approved by the State Bureau of Machinery Industry on May 20, 1999, and implemented on January 1, 2000
Radius size range
JB/T79801999
Radius size series
1, 1.25, 1.5, 1.75, 2, 2.25, 2.5. 2.753, 3.5, 4, 4.5, 5, 5.5, 6, 6.5
7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, 11, 11.5, 12, 12.5, 13, 13.5, 14, 14.515,15.5,16,16.5,17,17.5,18,18.5,19,19.5,20,21,22,23,24,25
3.3 The arc of the radius template measuring surface shall comply with the following provisions: Template width
Template original degree
Number of templates
a) For convex templates with a radius less than or equal to 10mm, the central angle subtended by the arc of its measuring surface shall be greater than 150°; for convex templates with a radius greater than 10mm, the chord length of the arc of its measuring surface shall be equal to the template width; b) For concave templates with a radius less than or equal to 14.5mm, the central angle subtended by the arc of its measuring surface shall be within the range of 80°~90°: for concave templates with a radius greater than 14.5mm, the central angle subtended by the arc of its measuring surface shall be greater than 45°. 4 Technical requirements
4.1 The surface of the radius template should not have defects that affect its performance. 4.2 The connection between the radius template and the protective plate should ensure that the template can be easily replaced. The template should be able to rotate smoothly around the screw or rivet axis without sticking or loosening.
4.3 Grouped radius templates should be arranged in order from small to large according to the radius size series. 4.4 The radius template should be made of 45# cold-rolled strip steel or high-quality carbon steel. 4.5 The hardness of the measuring surface of the radius template should not be less than 230HV. 4.6 The surface roughness R value of the measuring surface of the radius template is 1.6um. 4.7 The radius size and its limit deviation of the measuring surface of the radius template are shown in Table 2. Table 2
5 Marking and packaging
Diameter size
>10~18
>18~25
5.1 The protective plate of the group radius sample should be marked with: a) manufacturer's name or registered trademark; b) product name.
JB/T7980-1999
5.2 The radius size should be marked on each sample of the group radius sample. 5.3 The packaging box of the group radius sample should be marked with: a) manufacturer's name or registered trademark; b) product name and radius size range; c) standard number of this standard; d) factory date.
5.4 The radius sample should be treated with rust prevention before packaging and properly packaged, and shall not be damaged during transportation due to poor packaging. 5.5 The radius sample shall be accompanied by a product certificate that has been verified to meet the requirements of this standard; the product certificate shall have the standard number and factory date of this standard.
JB/T7980—1999
Appendix A
(Appendix to the standard)
Verification method of radius sample
This appendix specifies the verification method of radius sample for factory verification. A1 Appearance and grouping verification
Visually inspect the appearance according to 3.1. Check the radius size series of grouped radius sample according to Table 1. A2 Interaction verification
Check by hand that each sample can rotate smoothly around the screw or nail axis without any sticking or loosening. A3 Hardness verification
Verify with a Vickers hardness tester according to 3.5.
A4 Surface roughness verification
Compare and check with a surface roughness comparison sample according to 3.6. A5 Limit Deviation Verification
Enlarge the projector 10~20 times and compare it with the projector sample (see Figure A1), or use the proofreading sample to test by light transmission method (see Figure A2). When the convex sample to be tested is compared with the maximum limit size of the projector sample (or the proofreading sample of the maximum limit size), they should be in contact at the highest point of the arc surface, and the highest point of the arc surface of the convex sample to be tested should have a gradually increasing gap or no gap along the direction of the two ends. When the convex sample to be tested is compared with the minimum limit size of the projector sample (or the proofreading sample of the minimum limit size), they should be in contact at both ends of the arc surface, and the two ends of the arc of the convex sample to be tested should have a gradually increasing gap or no gap along the direction of the highest point. Conversely, when the concave sample to be tested is tested, the opposite result to the above should be obtained. Comparison sample
(minimum limit size)
maximum limit size
minimum limit size
inspected sample
proofing sample
(large limit size)
proofing sample
inspected sample
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