Steel wire rope----spliced eye termination for slings standard
Steel wire rope----spliced eye termination for slings standard
GB/T 16271-1996
Approved by the State Bureau of Technical Supervision on 1996-04-05 and implemented on 1996-10-01
This standard is equivalent to ISO 8794-1986 for technical content such as definitions, manual insertion methods, design requirements and test methods for cable ties. In other respects, this standard has made appropriate technical modifications according to the situation in our country, and added the appearance requirements and content of the spliced eye termination sling.
This standard, together with 《General Purpose Wire Rope Slings - Characteristics and Technical Conditions》 and GB 6946-93 《Wire Rope Aluminum Alloy Pressed Joints》, constitute the standard system for wire rope slings.
This standard stipulates the minimum requirements for plug-in general-purpose spliced eye termination for slings . Other national standards and industry standards have other provisions on the types of spliced eye termination slings for special purposes.
For example, GB 14738-93 《Technical Conditions for the Use of Wire Rope Slings for Handling in Ports》 and the industry standard《Safety Regulations for Hoisting Machinery Spreaders and Rigging》.
When using this standard, the provisions of these standards should be considered.
Appendix A and Appendix B of this standard are all prompt appendices.
This standard is proposed by the National Steel Standardization Technical Committee.
This standard is under the jurisdiction of the Information Standards Research Institute of the Ministry of Metallurgical Industry.
This standard is not equivalent to the international standard ISO 8794-1986.
1 Subject content and scope of application
This standard specifies the terminology, technical requirements, inspection methods and inspection rules for slings of wire rope slings.
The standard applies to hand and mechanically inserted wire rope slings (hereafter referred to as slings).
2 Reference standards
The following standards contain provisions which, through reference in this standard, constitute provisions of this standard, and at the time of publication, the editions indicated were valid. All standards are subject to revision and parties using this standard should explore the possibility of using the latest edition of the following standards.
GB/T 8918 steel wire rope
3 Terminology
3.1 spliced eye termination
Insert the ends of the strands into the main body of the wire rope reversely to form a loop hole or eyelet at the end of the wire rope (see Figures 1 and 2).
4 Technical requirements
4.1 Wire rope
4.1.1 Types of wire ropes
The type of wire rope used should be the wire rope with alternately twisted fiber core or metal core specified in GB 8918, but single-strand steel wire rope, special-shaped strand steel wire specified in GB 8918 Ropes and multi-strand wire ropes are excluded.
4.1.2 The tensile strengt of the steel wire should be 1570～1770MPa.
4.2 Design requirements of the spliced eye termination
4.2.1 The actual breaking strength of the spliced eye termination shall be at least 70% of the minimum breaking force of the corresponding wire rope.
Note: If the wire rope has a metal core, the metal core should be inserted at least three times, which can be regarded as the load-bearing part of the wire rope.
4.2.2 After 20,000 fatigue tests, the breaking force of the spliced eye termination shall comply with the provisions of Article 4.2.1.
4.2.3 In a single sling, the minimum distance between the weaving parts of the spliced eye termination at each end shall not be less than 10 times the nominal diameter of the wire rope.
4.3 Insertion operation
4.3.1 Interspersed times
4.3.1.1 Manual insertion
The weaving operation shall intersperse each strand at least five times, and at least three of the five times shall be interlaced with the whole strand.
Note: In order to obtain a smooth transition of the plug connector, the strands with part of the wire can be cut off for the last or second insertion.
4.3.1.2 Mechanical insertion
The insertion operation consists of three strands interspersed four times, and the other three strands are interspersed five times (interspersed 27 times).
4.3.1.3 According to the size, structure and insertion method of the wire rope, the number of insertions per strand may be more than the above-mentioned provisions.
4.3.2 Insertion method
The insertion methods specified in Appendix A and Appendix B are recommended.
4.3.3 The insertion operation should be carried out by the threading workers who have been strictly trained and have passed the examination.
4.4 Appearance of the buckle
4.4.1 The rope core of the inserted part shall not be exposed, and the strands shall be tight and shall not be loose.
4.4.2 The cut ends of the strands after insertion should be flat, and there should be no obvious distortion.
4.4.3 According to the requirements of the purchaser, the ends of the strands and wires of the inserted strands shall be wrapped with suitable coverings, but shall be specified in the contract.
5 Sampling
5.1 There are two types of spliced eye termination inspection: factory inspection and type inspection.
5.2 Factory inspection
5.2.1 Inspection and acceptance
The inspection and acceptance of the spliced eye termination shall be carried out by the technical supervision department of the supplier.
5.2.2 Batch rules
The spliced eye termination shall be accepted in batches, and each batch shall be composed of cable buckles made with the same wire rope specification, the same strength level, and the same insertion method.
5.2.3 Number of samples
5.2.3.1 The appearance, insertion length and insertion sequence of each spliced eye termination shall be checked.
5.2.3.2 Carry out the breaking force test of the spliced eye termination according to the sampling quantity specified in Table 1, and the sample shall meet the needs of the breaking tensile test of the cable buckle.
5.3 Type test
5.3.1 Type test shall be carried out in any of the following situations:
a) During the trial production appraisal of new products;
b) After the official production, such as the shape of the spliced eye termination, the structure of the wire rope, and the insertion method, there are major changes;
c) After the product has been discontinued for a long time, when the production is resumed;
d) When requested by the national quality supervision department.
Table 1 Number of samples
batch number samples/piece
≤100 2
＞100～200 4
>200 6
5.3.2 Number of samples
5.3.2.1 From the spliced eye termination made of the same wire rope specification, the same strength level and the same insertion method, choose 4 spliced eye termination for the test.
5.3.2.2 The appearance, insertion length and insertion sequence of each spliced eye termination shall be checked.
5.3.2.3 Carry out the fatigue test on thespliced eye termination first, and then carry out the breaking force test. The length of the sample should meet the requirements of the cable buckle fatigue test and breaking tensile test.
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5.4 Recheck and Judgment Rules
5.4.1 If all the tests meet the specified requirements, the batch of spliced eye termination is qualified.
5.4.2 If any item is unqualified, double sampling shall be carried out for inspection. If it is unqualified again, it shall be judged that the batch of spliced eye termination is unqualified.
6 Inspection methods
6.1 Check the appearance and insertion sequence of the spliced eye termination with the naked eye.
6.2 The insertion length shall be measured with a measuring tool with a division value of 1mm.
6.3 Tensile test at break
The length of the wire rope between the ends of the two buckle insert parts of the sling shall not be less than 30 times the nominal diameter of the wire rope. The clasp for each test shall not be fitted with a collar.
The tension is applied by passing a round pin of the appropriate diameter through the grommet.
First, quickly load it to 60% of the minimum breaking force of the wire rope specified in GB 8918; then, apply the stress smoothly at a rate of not more than 10MPa/s until to achieve the actual breaking force.
6.4 Fatigue test
The length of the wire rope between the ends of the two spliced eye termination shall be the same as in the breaking tensile test (see 5.3). Both lanyards should be fitted with thimbles.
The test shall be carried out on a tensile fatigue testing machine which shall be capable of showing a substantial amount of the same stress characteristic curve developed between the fixed and moving ends of the sling.
The sling should be able to withstand the alternating tension in the axial direction of the wire rope, and the alternating tension should be 15-30% of the minimum breaking tension of the wire rope specified in GB 8918.
During the test, the frequency of the testing machine shall not exceed 15 kHz.
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