Some standard content:
Mechanical Industry Standard of the People's Republic of China
JB/T8178-1999
Technical Specification of Cap for Cap and Pin Insulators1999-08-06 Issued
2000-01-01 Implementation
JB/T8178-1999
This standard is a revision of JB/T8178-95 "Technical Specification of Cap for Suspension Insulator" (JB/T8178-95 is the original national standard that has been downgraded to an industry standard but has not yet been converted) according to GB/T1.1-1993 "Guidelines for Standardization Work Unit 1: Rules for Drafting and Presentation of Standards Part 1: Basic Regulations for Standard Writing". This revision only modifies the writing format and rules. The technical content is basically the same as JB/T8178-95.
This standard shall replace JB/T8178-95 from the date of implementation. Appendix A of this standard is the appendix of the standard.
This standard is proposed and managed by the National Technical Committee for Standardization of Insulators. The drafting units of this standard are: Xi'an Electric Ceramics Research Institute and Shanghai Huafeng Steel Plant. The main drafters of this standard are: Cai Meicheng, Jin Haiming, Jiang Naitao, Li Danan. This standard is entrusted to Xi'an Electric Ceramics Research Institute for interpretation. Model map
Mechanical Industry Standard of the People's Republic of China
Technical conditions
Suspension insulator cap
Technical specirication of cap For capandpininsulatorsJB/T 81781999
Replaces JB/T\8178—95
This standard mainly specifies the technical requirements, test methods, inspection rules, marking and packaging of suspension insulator caps. This standard applies to caps (hereinafter referred to as caps) used for disc-shaped suspension porcelain or glass insulators of AC overhead power lines. 2 Reference standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When the standard is published, the versions shown are valid. All standards will be revised. Parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T775.3-1987
GB/T1348—1988
GB/T2900.8—1995
GB/T3177—1997
GB/T 4056-1994
GB/T5611--1985
GB/T94401988
JB/T33841999
JB/T7974-—1999
JB/T8177-1999
3 Definitions
Test methods for insulators Part 3 Test methods for ductile iron parts||t t||Electrical termsInsulator
Smooth workpiece size inspection
High-voltage line suspension insulator connection structure and sizeCasting terms
Mallet cast iron parts
High-voltage insulator sampling plan
Cast iron plate
General technical conditions for hot-dip galvanized layer of metal accessories of insulatorsThe terms used in this standard conform to the definitions of GB/T2900.8 and GB/T5611. 4 Classification and model
4.1 Iron caps are divided into two types according to the connection mode of the suspension insulator: ball-and-socket connection (Figure 1a, b) and slot connection (Figure 2). 4.2 Iron caps are divided into 9 levels according to the corresponding mechanical and electrical destructive strength levels of suspension insulators: 40, 70, 100, 120, 160, 210, 300, 400 and 530 kN.
4.3 The method of indicating the iron cap model is as follows:
口口口
一 indicates the strength grade kN value of the iron cap
indicates the letter of the insulating material L glass parts, porcelain parts do not indicate the letter indicating the iron type. Q ball wide connection; C slot type connection model example: Q210, indicating a 210kN grade iron cap with ball and socket connection for suspension porcelain insulators. Approved by the State Machinery Industry Bureau on August 6, 1999 and implemented on January 1, 2000
5 Technical requirements
JB/T8178—1999
5.1 The iron cap shall be manufactured according to the drawings approved by this standard and the prescribed procedures. The dimensions of the iron marriage are all the dimensions after hot-dip galvanizing. 5.2 The material properties of the iron cap shall meet the requirements of the materials and physical and chemical properties of the grades specified in GB/T9440 or GB/T1348. 5.3 Dimensional tolerances
5.3.1 The dimensions and tolerances of the connection structure of the iron cap shall comply with the provisions of GB/T4056. 5.3.2 The tolerances of other dimensions of the iron cap, except for those specified in the drawings, the depth of the inner cavity of the cap mouth, the thickness of the partition between the bottom of the cap socket or the bottom of the cap slot and the bottom of the inner cavity of the cap mouth (referred to as the partition thickness), the wall thickness and other dimensions shall comply with the provisions of Table 1 and Table 2. 5.4 Shape and position tolerances
5.4.1 The roundness of the two pin holes of the slotted iron cap slot and the coaxiality of their axes shall comply with the provisions of Appendix A of this standard. The roundness of the width shall not be greater than twice the absolute value of the CT9 grade deviation of the corresponding dimension in Table 2. 5.4.25
The flatness of the cap mouth shall not be greater than -1.0mm.
The cap socket, the pin hole of the locking device and the cap slot shall not have obvious skew. 5.4.4
The limit value of the core misalignment in the dotted line part of the iron cap (as shown in Figure 1) should not exceed 0.5mm, and the misalignment in other parts should not exceed 5.4.5
5.5 No cracks are allowed in the iron cap.
5.6 The inner and outer surfaces of the iron cap should be hot-dip galvanized, and the thickness of the zinc layer and the quality per unit area should comply with the relevant provisions of JB/T8177. Whether the uniformity of the zinc layer should be tested by the "sulfur-covered copper solution method" shall be agreed upon by the supply and demand parties, but the specific requirements shall comply with the relevant provisions of JB/T8177.
5.7 Appearance quality
5.7.1 The model and trademark of the iron cap should be clearly identifiable and the appearance should be regular. 5.7.2 The appearance quality of the zinc layer shall comply with the following provisions: JB/T8178-1999
a) The zinc layer shall be uniform and continuous, and yellow rust (acid reversion) is not allowed on the inner and outer surfaces of the iron cap; b) Zinc deficiency and zinc layer peeling are not allowed on the outer surface of the iron cap and the cap opening below the double-dash line (as shown in Figures 1 and 2); c) Zinc deficiency on the inner surface of the iron cap (except the cap opening below the double-dash line) shall comply with the relevant provisions of JB/T8177; d) Zinc piles, melt scars and zinc slag are not allowed on the dotted line part of the iron cap (as shown in Figures 1 and 2). Table 1 Dimensional tolerance grade of various parts of iron cap
Part name
Inner cavity depth of cap mouth
Thickness of partition
Other parts
Basic size
>10~16
>16~40
>40~100
>100~160
>160~250
>250~400
Table 2 Dimensional deviation value of iron cap
Tolerance grade CT
5.7.3 Other comprehensive appearance defects of iron cap shall comply with the following provisions: Poor
a) Iron cap The dotted line part should be flat, and no burrs, sand loss, pores or sand holes are allowed; mm
b) There should be no pores, sand holes with a diameter greater than 1mm and a depth greater than 0.5mm, and hair residues with a height greater than 1mm in the cap mouth below the double dotted line of the iron width;
c) The burrs, sand loss, pores and pinholes in the appearance of other parts other than those specified in items & and b of this article should not affect the performance of the iron cap (except for item c of Article 5.7.2 of this standard), assembly and installation connection requirements; and the height of any defect should not exceed 1mm, the depth should not exceed 1.5mm, and the pores should not exist at the corresponding positions of the inner and outer surfaces at the same time. 5.8 Mechanical tensile strength
The mechanical tensile failure load of the iron cap should comply with the standard value in Table 3, and the fracture of the iron cap after the mechanical tensile failure test should be uniform and dense without cracks.
Strength grade of iron sheet
Tensile failure load after mechanical drawing
Test method
6.1 Physical and chemical property test
Mechanical tensile failure load of iron cap
The physical and chemical property test of materials used to manufacture iron caps shall be carried out in accordance with the provisions of GB/T9440 or GB/T1348. 6.2 Appearance quality inspection
(To be determined
JB/T8178—1999
Appearance quality inspection shall be carried out by visual inspection or measuring tool inspection. If necessary, the supply and demand parties may negotiate and propose typical standard samples in advance for comparison and judgment. 6.3 Flaw detection inspection
Non-destructive flaw detection methods, such as magnetic inspection, shall be used for iron caps of 160kN and above. 6.4 Dimension inspection
The dimensions of the connection structure of the cap socket shall be checked by the gauge specified in GB/T4056, and the remaining dimensions shall be checked by a vernier caliper or a special sample. The accuracy of the vernier caliper shall be selected in accordance with the provisions of GB/T3177. 6.5 Shape and position tolerance inspection
6.5.1 The roundness of the two pin holes of the cap slot and the coaxiality of their axes shall be checked using the gauge specified in Appendix A. 6.5.2 The roundness of the cap mouth shall be checked with a vernier caliper or a special gauge. 6.5.3 For the flatness inspection of the cap mouth, the cap mouth of the iron cap shall be naturally placed on a plate with an accuracy of not less than Grade 3 as specified in JB/T7974, and the cap mouth and the plate shall be checked with a feeler gauge. 6.5.4 The inspection of the skewness of the cap socket, the pin hole of the locking device and the cap slot (Article 5.4.4) shall be conducted by visual observation. If necessary, the supply and demand parties may negotiate and propose typical standard samples in advance for comparison and judgment. 6.5.5 Check the core and type by visual inspection or measuring tools. 6.6 Mechanical tensile failure load test of iron cap
The strength test of iron cap is carried out by gluing into glue. The glued lead (Figure 3) should be made of high-quality carbon cable structural steel or other steel materials, glued with sulfur graphite or silicate cement adhesive or other equivalent methods to make it glued with the iron cap, and carry out according to the provisions of GB/T775.3. Iron powder
Adhesive
Strand wheel
6.7 Fracture inspection
Fracture inspection is carried out by visual observation.
6.8 Zinc layer quality test
The thickness of the zinc layer, the zinc layer mass per unit area and the copper sulfate solution method test shall be carried out in accordance with the provisions of JB/T8177. 7 Inspection rules
7.1 The supplier's quality inspection department shall inspect the drawings approved in accordance with the prescribed procedures, this standard and the technical agreement between the supplier and the buyer. The buyer has the right to re-inspect the quality of the iron caps in accordance with the provisions of this standard, or the supplier may provide the sampling test and material performance test results of the batch of iron caps upon agreement between the supplier and the buyer.
7.2 Iron caps shall be inspected in batches. Iron caps of the same model made by the same process method shall be regarded as a batch. The quantity of each batch shall be selected in accordance with the provisions of Table 6 of this standard.
7.3 The inspection of iron caps is divided into individual tests, sampling tests and type tests. 4
Individual tests
JB/T8178—1999
The iron caps submitted for inspection shall be inspected one by one in accordance with the provisions of Table 4. If any of the requirements specified in Table 4 are not met, the iron cap is unqualified.
Table 4 Test items one by one
Sampling test
7. 3. 2.2
Test items
Appearance quality inspection
Flaw detection inspection
Dimension inspection
Shape and position tolerance inspection
Test basisbzxz.net
Article 5.7 of this standard
Article 5.5 of this standard
Article 5.3.1 of this standard
Article 5.4 of this standard
Test method
Article 6.2 of this standard
Article 6.3 of this standard
Article 6.4 of this standard
Article 6.5.1 of this standard For the rest,
visual inspection and, if necessary, measuring tools shall be used
Random sampling shall be carried out in accordance with the provisions of this standard and JB/T3384 from each batch of iron caps that have passed the tests one by one. The test items, test basis, sampling plan, acceptance quality level and test method of iron cap sampling test shall comply with the provisions of Table 5 Table 5 Sampling test items
Acceptance quality
Test items
Gauge inspection of cap socket and cap groove
Dimension inspection
Shape and position tolerance inspection
Mechanical tensile strength test
Fractural inspection
Zinc layer quality test
Test basis
Articles 5.3.1 and 5.4.1 of this standard
Article 5.3.2 of this standard
Article 5.4 of this standard
(Except Article 5.4.1)
Article 5.8 of this standard
Article Article 5.8 of this standard
Article 5.6 of this standard
Sampling plan
Piecework secondary
Measuring secondary
Piecework secondary
(AQL)%
Test method
Article 6.4 and 6.5.1 of this standard
Article 6.4 of this standard
Article 6.5.2, 5.5.3,
6.5.4 and 6.5.5 of this standard
Article 6.6 of this standard
Article 6.7 of this standard
Article 6.8 of this standard
The batch size, sample capacity and judgment criteria of the sampling plan for each test of iron cap shall comply with the provisions of Tables 6, 7 and 8 respectively. Sampling test procedure: first randomly select the nth sample from batch N according to the provisions of Table 6, and perform the 1st, 2nd and 3rd inspections according to Table 5: then randomly distribute the samples according to Tables 7 and 8, and perform the 4th, 5th and 6th tests according to Table 5 respectively. Table 6 Judgment criteria for sampling test of size, shape and position tolerances Gauge inspection of grooves and slots
≤1200
1201~3200
3201~10000
Sample capacity
Acceptance judgment number
Sample capacity for the first extraction:
-Acceptance judgment number for the first sampling,
First sampling Rejection judgment number:
Rejection judgment number
Sample size of the second sampling;
Acceptance judgment number of the second sampling;
Rejection judgment number of the second sampling,
Other size inspection, other shape
and position tolerance inspection
Acceptance judgment number
Rejection judgment number
≤1200
1201~3200
3201~10000
Acceptance constant of the first sampling;
Rejection constant of the first sampling:
K, acceptance constant of the second sampling.
≤1200
1201~3200
3201~10000
JB/T8178—1999
Table 7 Judgment criteria for mechanical strength sampling test
Sample capacity
Mechanical tensile strength test
Judgment constant
Table 8 Judgment criteria for zinc layer quality sampling test
Sample capacity
Acceptance judgment number
Rejection judgment number
Zinc layer quality test judgment
The judgment of the test results shall comply with the relevant provisions of
JB/T8177
7.3.2.4 The judgment procedure for piece sampling plan, the judgment procedure for measurement sampling plan and the calculation procedure shall be carried out in accordance with the provisions of this standard and JB/T3384.
Determination procedure of piece-rate secondary sampling plan. Randomly select the first sample n from the batch N and conduct the test. If the number of defective products d,≤Ai in n, then accept the batch; if d≥R.1, then reject the batch. If A1 The drawings, this standard and the technical agreement between the supplier and the buyer approved in accordance with the prescribed procedures shall be inspected by the supplier's quality inspection department. The buyer has the right to re-inspect the quality of the iron caps in accordance with the provisions of this standard, or the supplier may provide the sampling test and material performance test results of the batch of iron caps upon agreement between the supplier and the buyer.
7.2 Iron caps shall be inspected in batches. Iron caps of the same model made by the same process method shall be considered as a batch. The quantity of each batch shall be selected in accordance with the provisions of Table 6 of this standard.
7.3 The inspection of iron caps is divided into individual tests, sampling tests and type tests. 4
Each-by-Each Test
JB/T8178—1999
The iron caps submitted for inspection shall be inspected one by one in accordance with the provisions of Table 4. If any of the requirements specified in Table 4 are not met, the iron cap shall be unqualified.
Table 4 Individual Test Items
Sampling Test
7. 3. 2.2
Test items
Appearance quality inspection
Flaw detection inspection
Dimension inspection
Shape and position tolerance inspection
Test basis
Article 5.7 of this standard
Article 5.5 of this standard
Article 5.3.1 of this standard
Article 5.4 of this standard
Test method
Article 6.2 of this standard
Article 6.3 of this standard
Article 6.4 of this standard
Article 6.5.1 of this standard For the rest,
visual inspection and, if necessary, measuring tools shall be used
Random sampling shall be carried out in accordance with the provisions of this standard and JB/T3384 from each batch of iron caps that have passed the tests one by one. The test items, test basis, sampling plan, acceptance quality level and test method of iron cap sampling test shall comply with the provisions of Table 5 Table 5 Sampling test items
Acceptance quality
Test items
Gauge inspection of cap socket and cap groove
Dimension inspection
Shape and position tolerance inspection
Mechanical tensile strength test
Fractural inspection
Zinc layer quality test
Test basis
Articles 5.3.1 and 5.4.1 of this standard
Article 5.3.2 of this standard
Article 5.4 of this standard
(Except Article 5.4.1)
Article 5.8 of this standard
Article Article 5.8 of this standard
Article 5.6 of this standard
Sampling plan
Piecework secondary
Measuring secondary
Piecework secondary
(AQL)%
Test method
Article 6.4 and 6.5.1 of this standard
Article 6.4 of this standard
Article 6.5.2, 5.5.3,
6.5.4 and 6.5.5 of this standard
Article 6.6 of this standard
Article 6.7 of this standard
Article 6.8 of this standard
The batch size, sample capacity and judgment criteria of the sampling plan for each test of iron cap shall comply with the provisions of Tables 6, 7 and 8 respectively. Sampling test procedure: first randomly select the nth sample from batch N according to the provisions of Table 6, and perform the 1st, 2nd and 3rd inspections according to Table 5: then randomly distribute the samples according to Tables 7 and 8, and perform the 4th, 5th and 6th tests according to Table 5 respectively. Table 6 Judgment criteria for sampling test of size, shape and position tolerances Gauge inspection of grooves and slots
≤1200
1201~3200
3201~10000
Sample capacity
Acceptance judgment number
Sample capacity for the first extraction:
-Acceptance judgment number for the first sampling,
First sampling Rejection judgment number:
Rejection judgment number
Sample size of the second sampling;
Acceptance judgment number of the second sampling;
Rejection judgment number of the second sampling,
Other size inspection, other shape
and position tolerance inspection
Acceptance judgment number
Rejection judgment number
≤1200
1201~3200
3201~10000
Acceptance constant of the first sampling;
Rejection constant of the first sampling:
K, acceptance constant of the second sampling.
≤1200
1201~3200
3201~10000
JB/T8178—1999
Table 7 Judgment criteria for mechanical strength sampling test
Sample capacity
Mechanical tensile strength test
Judgment constant
Table 8 Judgment criteria for zinc layer quality sampling test
Sample capacity
Acceptance judgment number
Rejection judgment number
Zinc layer quality test judgment
The judgment of the test results shall comply with the relevant provisions of
JB/T8177
7.3.2.4 The judgment procedure for piece sampling plan, the judgment procedure for measurement sampling plan and the calculation procedure shall be carried out in accordance with the provisions of this standard and JB/T3384.
Determination procedure of piece-rate secondary sampling plan. Randomly select the first sample n from the batch N and conduct the test. If the number of defective products d,≤Ai in n, then accept the batch; if d≥R.1, then reject the batch. If A1 The drawings, this standard and the technical agreement between the supplier and the buyer approved in accordance with the prescribed procedures shall be inspected by the supplier's quality inspection department. The buyer has the right to re-inspect the quality of the iron caps in accordance with the provisions of this standard, or the supplier may provide the sampling test and material performance test results of the batch of iron caps upon agreement between the supplier and the buyer.
7.2 Iron caps shall be inspected in batches. Iron caps of the same model made by the same process method shall be considered as a batch. The quantity of each batch shall be selected in accordance with the provisions of Table 6 of this standard.
7.3 The inspection of iron caps is divided into individual tests, sampling tests and type tests. 4
Each-by-Each Test
JB/T8178—1999
The iron caps submitted for inspection shall be inspected one by one in accordance with the provisions of Table 4. If any of the requirements specified in Table 4 are not met, the iron cap shall be unqualified.
Table 4 Individual Test Items
Sampling Test
7. 3. 2.2
Test items
Appearance quality inspection
Flaw detection inspection
Dimension inspection
Shape and position tolerance inspection
Test basis
Article 5.7 of this standard
Article 5.5 of this standard
Article 5.3.1 of this standard
Article 5.4 of this standard
Test method
Article 6.2 of this standard
Article 6.3 of this standard
Article 6.4 of this standard
Article 6.5.1 of this standard For the rest,
visual inspection and, if necessary, measuring tools shall be used
Random sampling shall be carried out in accordance with the provisions of this standard and JB/T3384 from each batch of iron caps that have passed the tests one by one. The test items, test basis, sampling plan, acceptance quality level and test method of iron cap sampling test shall comply with the provisions of Table 5 Table 5 Sampling test items
Acceptance quality
Test items
Gauge inspection of cap socket and cap groove
Dimension inspection
Shape and position tolerance inspection
Mechanical tensile strength test
Fractural inspection
Zinc layer quality test
Test basis
Articles 5.3.1 and 5.4.1 of this standard
Article 5.3.2 of this standard
Article 5.4 of this standard
(Except Article 5.4.1)
Article 5.8 of this standard
Article Article 5.8 of this standard
Article 5.6 of this standard
Sampling plan
Piecework secondary
Measuring secondary
Piecework secondary
(AQL)%
Test method
Article 6.4 and 6.5.1 of this standard
Article 6.4 of this standard
Article 6.5.2, 5.5.3,
6.5.4 and 6.5.5 of this standard
Article 6.6 of this standard
Article 6.7 of this standard
Article 6.8 of this standard
The batch size, sample capacity and judgment criteria of the sampling plan for each test of iron cap shall comply with the provisions of Tables 6, 7 and 8 respectively. Sampling test procedure: first randomly select the nth sample from batch N according to the provisions of Table 6, and perform the 1st, 2nd and 3rd inspections according to Table 5: then randomly distribute the samples according to Tables 7 and 8, and perform the 4th, 5th and 6th tests according to Table 5 respectively. Table 6 Judgment criteria for sampling test of size, shape and position tolerances Gauge inspection of grooves and slots
≤1200
1201~3200
3201~10000
Sample capacity
Acceptance judgment number
Sample capacity for the first extraction:
-Acceptance judgment number for the first sampling,
First sampling Rejection judgment number:
Rejection judgment number
Sample size of the second sampling;
Acceptance judgment number of the second sampling;
Rejection judgment number of the second sampling,
Other size inspection, other shape
and position tolerance inspection
Acceptance judgment number
Rejection judgment number
≤1200
1201~3200
3201~10000
Acceptance constant of the first sampling;
Rejection constant of the first sampling:
K, acceptance constant of the second sampling.
≤1200
1201~3200
3201~10000
JB/T8178—1999
Table 7 Judgment criteria for mechanical strength sampling test
Sample capacity
Mechanical tensile strength test
Judgment constant
Table 8 Judgment criteria for zinc layer quality sampling test
Sample capacity
Acceptance judgment number
Rejection judgment number
Zinc layer quality test judgment
The judgment of the test results shall comply with the relevant provisions of
JB/T8177
7.3.2.4 The judgment procedure for piece sampling plan, the judgment procedure for measurement sampling plan and the calculation procedure shall be carried out in accordance with the provisions of this standard and JB/T3384.
Determination procedure of piece-rate secondary sampling plan. Randomly select the first sample n from the batch N and conduct the test. If the number of defective products d,≤Ai in n, then accept the batch; if d≥R.1, then reject the batch. If A8
The batch, sample capacity and judgment criteria of the sampling plan for each test of the iron cap shall comply with the provisions of Tables 6, 7 and 8 respectively. Sampling test procedure: First, randomly select the nth sample from the batch N according to the provisions of Table 6, and perform the 1st, 2nd and 3rd inspections according to Table 5: Then, randomly distribute the samples according to Tables 7 and 8, and perform the 4th, 5th and 6th tests according to Table 5 respectively. Table 6 Judgment criteria for sampling tests of size, shape and position tolerances Gauge inspection of grooves and slots
≤1200
1201~3200
3201~10000
Sample capacity
Acceptance judgment number
Sample capacity for the first draw:
-Acceptance judgment number for the first sampling,
First sampling Rejection judgment number:
Rejection judgment number
Sample size of the second sampling;
Acceptance judgment number of the second sampling;
Rejection judgment number of the second sampling,
Other size inspection, other shape
and position tolerance inspection
Acceptance judgment number
Rejection judgment number
≤1200
1201~3200
3201~10000
Acceptance constant of the first sampling;
Rejection constant of the first sampling:
K, acceptance constant of the second sampling.
≤1200
1201~3200
3201~10000
JB/T8178—1999
Table 7 Judgment criteria for mechanical strength sampling test
Sample capacity
Mechanical tensile strength test
Judgment constant
Table 8 Judgment criteria for zinc layer quality sampling test
Sample capacity
Acceptance judgment number
Rejection judgment number
Zinc layer quality test judgment
The judgment of the test results shall comply with the relevant provisions of
JB/T8177
7.3.2.4 The judgment procedure for piece sampling plan, the judgment procedure for measurement sampling plan and the calculation procedure shall be carried out in accordance with the provisions of this standard and JB/T3384.
Determination procedure of piece-rate secondary sampling plan. Randomly select the first sample n from the batch N and conduct the test. If the number of defective products d,≤Ai in n, then accept the batch; if d≥R.1, then reject the batch. If A8
The batch, sample capacity and judgment criteria of the sampling plan for each test of the iron cap shall comply with the provisions of Tables 6, 7 and 8 respectively. Sampling test procedure: First, randomly select the nth sample from the batch N according to the provisions of Table 6, and perform the 1st, 2nd and 3rd inspections according to Table 5: Then, randomly distribute the samples according to Tables 7 and 8, and perform the 4th, 5th and 6th tests according to Table 5 respectively. Table 6 Judgment criteria for sampling tests of size, shape and position tolerances Gauge inspection of grooves and slots
≤1200
1201~3200
3201~10000
Sample capacity
Acceptance judgment number
Sample capacity for the first draw:
-Acceptance judgment number for the first sampling,
First sampling Rejection judgment number:
Rejection judgment number
Sample size of the second sampling;
Acceptance judgment number of the second sampling;
Rejection judgment number of the second sampling,
Other size inspection, other shape
and position tolerance inspection
Acceptance judgment number
Rejection judgment number
≤1200
1201~3200
3201~10000
Acceptance constant of the first sampling;
Rejection constant of the first sampling:
K, acceptance constant of the second sampling.
≤1200
1201~3200
3201~10000
JB/T8178—1999
Table 7 Judgment criteria for mechanical strength sampling test
Sample capacity
Mechanical tensile strength test
Judgment constant
Table 8 Judgment criteria for zinc layer quality sampling test
Sample capacity
Acceptance judgment number
Rejection judgment number
Zinc layer quality test judgment
The judgment of the test results shall comply with the relevant provisions of
JB/T8177
7.3.2.4 The judgment procedure for piece sampling plan, the judgment procedure for measurement sampling plan and the calculation procedure shall be carried out in accordance with the provisions of this standard and JB/T3384.
Determination procedure of piece-rate secondary sampling plan. Randomly select the first sample n from the batch N and conduct the test. If the number of defective products d,≤Ai in n, then accept the batch; if d≥R.1, then reject the batch. If A
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