QB/T 2349-1997 Carp Joint Pliers QB/T2349-1997 Standard Download Decompression Password: www.bzxz.net

QB/T2349-—1997
This standard is an industry standard developed on the basis of the original GB/T4953-1985 "Carp Pliers". In addition to the double hole accuracy requirements for carp pliers, this standard has made appropriate adjustments to some test methods and test values. This standard will replace GB/T4953-1985 from the date of implementation. This standard is proposed by the Quality and Standards Department of the China Light Industry Federation. This standard is under the jurisdiction of the National Tool Hardware Standardization Center. The responsible drafting unit of this standard is Shanghai Tool Industry Research Institute; participating drafting units are: Shanghai Forging Machine Tool Factory No. 3, Shanghai Labor Machinery Factory and Jiangsu Jiangyan Dahua Tool Factory.
The main drafters of this standard are: Lin Meide, Xue Guilun, Zhou Yanmou, Wang Qinguan, and Guan Shoujin. 682
1 Scope
Light Industry Standard of the People's Republic of China
Carp Joint Pliers
QB/T2349-1997
This standard specifies the types and basic dimensions, technical requirements, test methods, inspection rules and packaging, marking, transportation and storage of carp joint pliers. This standard applies to carp joint pliers for random repair and household use. 2 Referenced Standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T 230--1991
Metal Rockwell hardness test method
GB/T 343---1994
Low carbon steel wire for general purpose
GB/T 2828--1987
GB/T 4955-1985
GB/T 5305-1985
GB/T 6462---1986
3 Types and basic dimensions
3.1 Types
Batch inspection Sampling procedure and sampling table by attributes (applicable to inspection of continuous batches) Measurement of thickness of metal coatings Coulometric method by anodic dissolution Packaging, marking, transportation and storage of hand tools Cross-sectional thickness of metal and oxide coatings Microscope measurement method The type of carp-joint pliers is shown in Figure 1.
3.2 Basic dimensions
The basic dimensions of the carp-joint pliers shall be as specified in Table 1.
Approved by China Light Industry General Association on January 16, 1998
Types of carp-joint pliers
Implemented on September 1, 1998
3.3 Marking examples
Basic dimensions
QB/T2349—1997
Basic dimensions
The marking of carp-joint pliers consists of the product name, specification and standard number. Example: The marking of 125mm carp-joint pliers is:
Carp-joint pliers 125QB/T2349
4 Technical requirements
4.1 Hardness
The hardness of the jaws of the carp-joint pliers shall not be less than 44HRC, and the hardness of the pliers shaft shall not be less than 35HRC. 4.2 Handle strength
Slip joint pliers must have the strength specified in Table 2. Table 2 Handle strength
4.3 Shearing performance
Additional cutting distance Li, mm
Slip joint pliers should be able to smoothly cut the steel wire specified in GB/T 343. 4.4 Assembly accuracy
4.4.1 The assembly accuracy of the slip joint pliers should comply with the requirements of Figure 2 and Table 3. 684
Load FN
Permanent deformation S, mm
QB/T2349--1997
Figure 2 Assembly accuracy
Table 3 Assembly accuracy
Aa(max)
4.4.2 The slip joint pliers should be flexible to open and close, and the single and double holes should be easy to adjust without blocking. 4.5 Surface treatment
Ah(max)
An(max)
Slip joint pliers shall be electroplated, and the coating shall be uniform in color and free of defects such as pores, plating leakage, burning and delamination. The coating thickness shall not be less than 8μm. bZxz.net
4.6 Surface quality
4.6.1 The surface of the slip joint pliers shall not have defects such as cracks, burrs, scars and rust spots. 4.6.2
The outer side of the handle of the slip joint pliers shall have a clear pattern. For pliers with sheaths, the sheath shall be of uniform thickness and shall not have defects such as cracks, burrs, bubbles, etc. 4.6.3
The surface roughness R. value of the tooth surface and cutting edge of the slip joint pliers shall not be greater than 12.5um. 5
Test method
Dimension inspection
The dimensions of the slip joint pliers shall be inspected with universal measuring tools. 5.2 Inspection of assembly accuracy
5.2.1 The opening and closing flexibility of the carp-joint pliers shall be inspected by hand. 5.2.2 The assembly accuracy of the carp-joint pliers shall be inspected with a universal measuring tool. 5.3 Inspection of surface treatment
The thickness of the electroplating layer of the carp-joint pliers shall be inspected in accordance with the provisions of GB/T4955. In case of dispute, arbitration inspection shall be carried out in accordance with the provisions of GB/T6462.
5.4 Inspection of surface quality
QB/T 2349—1997
The surface quality of the carp-joint pliers shall be inspected by visual inspection, and its surface roughness shall be inspected by comparison with a standard sample block. 5.5 Hardness test
The hardness of the carp-joint pliers shall be tested in accordance with the provisions of GB/T230 at the position shown in Figure 3. Cutting edge test part
Clamp shaft test part
Figure 3 Hardness test part
5.6 Clamp handle strength test
As shown in Figure 4, a steel test piece with a thickness of 3mm and a hardness of 30-40HRC is clamped in the fine teeth part of the carp joint pliers and placed in the fixture of a special testing machine. A load of 50N is applied at a position L from the center of the clamp shaft, and the width b1 between the two clamp handles is measured at this time. The load is continued to be increased to the rated value specified in Table 2, and then the load is unloaded to 50N. The width b2 between the two clamp handles is measured at this time. The permanent deformation S (S=b-b2) must comply with the requirements of Table 2.
If it is difficult to apply load on the position of the pliers handle at a distance from the pliers axis L, then a suitable load application point can be selected at a distance from the axis L', and the load F can be calculated by formula (1): F
(8±1) mm
Figure 4 Clamp handle strength test
5.7 Shear performance test
（1）
The shear performance test of carp pliers uses the steel wire specified in GB/T343 as the test material, and its specifications and performance are specified in Table 4. During the test, the test material is placed on the same part of the blade and cut three times continuously by hand force. After the test, the carp pliers should not show any abnormality. 686
6 Inspection rules
QB/T2349—1997
Table 4 Specifications and properties of test materials
Test material diameter, mm
Tensile strength, MPa
6.1 Products shall be inspected and qualified by the quality inspection department of the manufacturer before leaving the factory, and shall be accompanied by a product certificate. 6.2 The ordering party may conduct random inspections on the products in accordance with the provisions of this standard. 6.3 The delivery inspection of products shall be carried out in accordance with the secondary sampling plan specified in GB/T2828. 6.4 The classification of unqualified products, the acceptable quality level (AQL) (number of unqualified products per 100 units) and the inspection level (IL) of the products shall be in accordance with the provisions of Table 5. Table 5 Classification and grouping of non-conforming products, acceptable quality level (AQL) and inspection level (IL) Classification and grouping of non-conforming products
Inspection items
Strength of pliers handle
Shearing performance
Powder surface treatment
Basic dimensions
Assembly accuracy
Surface roughness
Appearance quality
6.5 The judgment of whether the factory inspection is qualified or not shall be carried out in accordance with 4.11 of GB/T2828-1987. AQL
6.6 The manufacturer shall replace the non-conforming products found in the inspection and the samples after the destructive test. 6.7 The batches of products rejected by the inspection may be classified or repaired by the manufacturer and resubmitted for acceptance. 7 Packaging, marking, transportation, compensation and storage
7.1 Necessary anti-rust measures shall be taken for the slip-joint pliers, so that they have an anti-rust period of not less than one year. 7.2 The packaging, labeling, transportation and storage of products shall comply with the provisions of GB/T5305.
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