JB/T 58652-1999 This standard is a revision of JB/T 58652-93 "Quality Grade Assessment of Fastener Products". This standard specifies the principles and methods for the quality grade assessment of various types of fastener products produced in accordance with national standards and industry standards. It can also be used as a reference when assessing the quality grade of fastener products produced in accordance with other standards. This standard is applicable to the quality grade assessment of fastener products. This standard was first published on the date of year. JB/T 58652-1999 Quality Grade Assessment of Fastener Products JB/T58652-1999 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
JE/T 58651.1~58651.14-1999
JB/T58652-1999
Fastener Product Quality Grading
(Internal Use)
1999-12-30 Issued
National Bureau of Machinery Industry
2000-06-01 Implementation
JB/T5B652—1999
Not a standard [T5B652-93 Fastener Product Quality Grading Assessment Revision The original standard was revised: The main content of this standard is not required, and this standard is implemented from the point of view of the National Tightness Standardization Technical Committee. . The drafting units of this standard are: Shenyang Standard Parts Research Institute, Machinery Standardization Research Institute. 55
Mechanical Industry Standard of the People's Republic of China
Quality Grade Assessment of Fastener Products
(Internal Use)
JB/T 58652-1999
J3T58552-93
This standard specifies the principles and methods for quality grade assessment of fastener products produced according to national standards and industry standards. It also specifies the quality grade of solidifying products produced according to the standard. The standard can be used to assess the quality of fastener products. If the source of non-standard products is not used, five specifications (which can be different in length or diameter) can be selected for the product variety to be assessed. There are five different batches of solid specification sheets. Each grid sample is 8F pieces. Among the five specifications, if any specification is judged as unqualified due to mechanical performance, the station will directly judge it as unqualified and will not be included in the grading. If it is unqualified due to non-mechanical performance, it can still participate in the grading. 2 Reference standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, all versions will be in effect, and all standards will be suspended. All parties using this standard should discuss the possibility of using the following standards to report new versions. 58651.t—1
JBT 58651.2--[999
JH/T58651.3...1999
J8T5865141999
JB/T58651.51999
551.6—19www.bzxz.net
IB:T $8651.71999
JB/T 58631.8--1999
JB/T 58651.91999
General rules for fastener product classification
Fixed fastener product classification screw
Fixed fastener product quality classification screw
Fixed fastener product quality classification nut
Fastener product quality classification machine screw
Fastener product quality classification set screw
Fastener product quality classification external
Inner concave head
Fastener product quality classification
Self-tapping screw
Fastener product quality classification
Fastener product quality classification
JB/T58651.10—1999
JB/T58651.11-[999Fastener product quality classification copper nail
JB/T5 8651.12-1 Quality Grading of Fastener Products JB/T5865113-19 Quality Grading of Fastener Products Lifting Rings and Nails (Nuts) JB.58651.14—[999 Case Talk Fastener Products Quality Grading Lightweight Reverse Connection Brush 3 Assessment Basis
3.1 This standard adopts the percentage system, with a full score of 100. According to the quality grade, the base point standard score of the variety and the sample point standard score are determined. The base point standard score of the sample is one tenth of the base point standard score of the variety, and the difference is the difference between the base point standard score of the sample at this level and the base point standard score of the upper level sample. Approved by the Beijing Machinery Industry Bureau on December 30, 1999 56
2000-06-01 Field
JB/T58652—1999
The base point standard score and the difference of the product and the recommended standard are determined according to Table 1. 3.2 The quality level of samples shall be calculated in accordance with IB/T5865L1-58651.14. 3.3 This standard specifies that the sample quality level of the product is given a weighted score M of different quality. The sample quality level of qualified products is positive, and the sample quality level of qualified products is negative. Table 1
Classification
Quality products
Technical joint products
4 Calculation formula
Category center standard score
Common score of this sheet
Sample does not point to group score
4. According to the sample point score difference and unit defect score F, the quality weighted score is calculated by interpolation [F, and the calculation formula is as follows: Below: Superior products:
Qualified products:
Unqualified products:
In the formula: CuC, ChC-
Standard score difference of sample base points of each quality grade, see the values ​​of C, F, F-the smallest unit defect score of samples of each quality grade, calculated according to the provisions of JR/T5865L1-5SJJ4: Unit defect score of one sample.
4.7 The actual standard score M of a sample is the sum of the sample base standard score N and the quality weighted score H: M=N+M
4.3 The actual standard score of a product variety is the sum of the actual standard scores of the five samples: (N,+M..)
5 Quality grade assessment
The quality grade of a product variety is the actual standard score M of the variety, which is determined according to Table 2 to assess its quality grade. 57
Quality grade
Superior product
Qualified product
Compatible product
JE/T586521999
Quality score
90 75
T5 > 14, 3 50
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