This standard specifies the structural type, size, technical requirements, test and inspection, marking, packaging, transportation and storage of lifting clamps. This standard applies to lifting clamps for lifting steel plates, round steel, rails and I-beams in slings. Other lifting clamps can also be used for reference. JB/T 7333-1994 Lifting Clamps JB/T7333-1994 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
Lifting Clamps
1 Subject Content and Scope of Application
JB/T 7333-94
This standard specifies the structural type, size, technical requirements, testing and inspection, marking, packaging, transportation and storage of lifting clamps. This standard applies to lifting clamps (hereinafter referred to as lifting clamps) for lifting steel plates, round steel, rails and I-beams in slings. Other lifting clamps can also be used for reference.
2 Reference Standards
GB699 Technical Conditions for High-quality Carbon Structural Steel
Carbon Structural Steel
GB1591
GB3077
Low-alloy Structural Steel
Technical Conditions for Alloy Structural Steel
GB/T 12469
Welding quality assurance Requirements and defect classification of steel fusion welded joints General technical conditions for packaging of electromechanical products
GB/T13384
Painting and safety marking of mining, engineering, lifting and transportation machinery products JB2299
JB/ZQ4000.3 General technical requirements for welded parts JB/ZQ4000.7 General technical requirements for forgings
3 Types and basic parameters||tt| |3.1 Type
3.1.1 Lifting clamps are divided into the following types according to their uses (see Figures 1 to 6): a.
Vertical steel plate lifting clamps, whose product code is DSQ; horizontal steel plate lifting clamps, whose product code is DHQ; simple horizontal steel plate lifting clamps, whose product code is DHQJ; round steel lifting clamps, whose product code is DYQ; rail lifting clamps. Its product code is DGQ; f. I-beam lifting clamps, whose product code is DZQ. 3.1.2 Marking
3.1.2.1 Model indication method
Rated lifting capacity, unit
Product code (see Article 3.1.1)
3.1.2.2 Marking example:
a. The vertical lifting steel plate lifting clamp with a rated lifting capacity of 0.5t is marked as: Lifting clamp DSQ0.5
Approved by the Ministry of Machinery Industry of the People’s Republic of China on July 18, 1994 178
JB/T 7333--94
Implementation on July 1, 1995
JB/T7333-94
b. The round steel lifting clamp with a rated lifting capacity of 0.63t is marked as: Lifting clamp DYQ0.63JB/T7333-94
3.2 Basic parameters and sizes
The basic parameters and sizes of the vertical lifting steel plate lifting clamp are shown in Table 1. 3.2.1
The basic parameters and sizes of the horizontal lifting steel plate lifting clamp are shown in Table 23.2.3 The basic parameters and sizes of the simple horizontal lifting steel plate lifting clamp are shown in Table 3. 3.2.4 The basic parameters and sizes of the round steel lifting clamp are shown in Table 4. 3.2.5 The basic parameters and sizes of the rail lifting clamp are shown in Table 5. 3.2.6
The basic parameters and sizes of the I-beam lifting clamp are shown in Table 6. Figure 1 Lifting clamp for vertical lifting of steel plate
1 lifting ring; 2—clamp body; 3--safety device: 4-handle; 5-tension spring; 6. connecting rod; 7—clamp shaft 8—clamp tongue 9.-jaw pad Table 1
Rated lifting capacity
Test load
Opening degree A
JB/T7333-
Lifting clamp for horizontal lifting of steel plate
Clamp shaft; 3--safety device; 4--tension spring; 5-…--clamp tongue; 2--
Clamp body; 6-jaw pad
Rated lifting capacity
Test load
Opening degree A
0～ 25
Note: The rated lifting capacity in the table refers to lifting clamps used in pairs, and the angle of the lifting point is 60° (see Article 4.1) Figure 3 Simple lifting clamp for horizontal lifting of steel plates
1·Axis: 2—
Clamp tongue: 3-Clamp body
Rated lifting capacity
Test load
Opening degree A
Note: The rated lifting capacity in the table refers to lifting clamps used in pairs. The angle of the lifting point is 60\ (see Article 4.1). 180
10~~75
Rated lifting capacity
JB/T7333
Figure 4 Round steel lifting clamp
1-Clamp shaft: 2-Clamp tongue: 3-Clamp body
Test load
Figure 5 Rail lifting clamp
1-Shackle; 2-Pull plate: 3-Connecting shaft: 4-Clamp shaft; 5-Clamp platem
180100
$100 - called 130
Rated lifting capacity
JB/T7333-94
Test load
I-beam lifting clamp
1-clamp plate; 2-clamp shaft; 3-clamp body: 1-clamp pad Table 6
Rated lifting capacity
Test load
Opening A
Note: The rated lifting capacity in the table refers to the lifting clamps used in pairs. The lifting point angle is 60° (see 4.1). 4 Technical requirements
The rated lifting capacity of the lifting clamps used in pairs is the rated load when the lifting point angle is 60°. All kinds of lifting clamps should be manufactured according to the drawings and technical documents approved by the prescribed procedures. 4.2
4.3 Material
The mechanical properties of the materials used for the clamp shaft, clamp tongue and jaw pad should not be lower than 40Cr in GB3077. 4.3.1
4.3.2 The mechanical properties of the materials used for the pliers body and pliers plate shall not be lower than 40Cr and 16Mn in GB3077 and GB1591. 4.3.3 The mechanical properties of the materials used for the connecting shaft and the pull plate shall not be lower than 45 steel (for shaft) and 35 steel in GB699. 4.3.4 The mechanical properties of the materials used for other processed parts such as lifting rings and handles shall not be lower than Q235-A in GB700. 4.4 The technical requirements for forgings shall comply with the provisions of JB/ZQ4000.7. Rail model
15 ~ 22
I-beam model
10-~16
18 ~ 22
25~-32
4.5 The surface of forgings should be smooth and free of cracks, folds, overburning and internal defects that affect product performance. Welding repairs are not allowed for defects in forgings. 182
JB/T 7333-94
The technical requirements for welded parts should comply with the provisions of JB/ZQ4000.3. 4.6
4.7 The strength of the weld should not be lower than the strength of the parent material. The welding quality of important welds should meet the requirements of Class II in GB/T12469. 4.8 Assembly
4.8.1 All parts and components must be inspected and qualified by the inspection department. Purchased parts and outsourced parts must have a certificate of conformity before assembly. 4.8.2 The movable parts of the lifting clamp should be able to move flexibly without obstruction or friction. 4.9 Painting
4.9.1 The paint color and safety signs of the product should comply with the provisions of JB2299. 4.9.2 The painted parts of the product must be cleaned before painting. Puttying is strictly prohibited. The paint should be firm, beautiful, generous, smooth in appearance, and consistent in color, without marks, sagging, shrinkage, bubbles, shedding, roughness and inequality. 4.9.3 The unpainted parts of the product should be treated with rust prevention. 5 Tests
5.1 Static load test
5.1.1 Each product must undergo a static load test, and the test load is twice the rated lifting capacity of the product. 5.1.2 The test load shall be added gradually, and the suspension time shall not be less than 3 minutes. After unloading, check all parts. There shall be no cracks, permanent deformation, paint peeling or damage that affects performance and safety. There shall be no looseness or damage at the connection. The increase in the opening shall not exceed 0.25% of the original opening.
5.2 Dynamic load test
5.2.1 The test load is 1.25 times the rated lifting capacity. 5.2.2 The speed must be limited to the normal working range during the test. 5.2.3 During the test, the action of each mechanism of the lifting clamp shall be repeatedly tested, and the continuous cumulative time shall not be less than 10 minutes. After the test, visual inspection shall be conducted. All components shall not be damaged, and there shall be no looseness or damage at the connection. 5.3 Breaking test
5.3.1 The test load is 4 times the rated lifting capacity. 5.3.2 The test load shall be gradually added to the specified value and maintained for 5 minutes. It is required to be able to reliably support the load. 6 Inspection
Factory InspectionWww.bzxZ.net
6.1.1 Each product leaving the factory must be inspected and qualified by the inspection department of the manufacturer before it can be shipped. The products leaving the factory must have a certificate of conformity. 6.1.2 Factory inspection items include appearance inspection and static load test (see 5.1). The requirements for appearance inspection are as follows: All parts must not have harmful defects such as cracks and rust; a.
b. The appearance of the product should be intact and the assembly should be correct; c.
All moving parts should be flexible and reliable.
6.2 Type Inspection
Type inspection should be carried out when any of the following situations occurs: a.
Trial type identification of new products or old products for transfer to factory production; whenever there are changes in design, process and materials used; during normal production, each type of lifting clamp should be tested at least once a year; when production is resumed after a year of suspension;
when the factory inspection results are significantly different from the last type inspection. 6.2.1 Inspection items include: appearance inspection, static load test, dynamic load test and breaking test. The inspection must be carried out by full-time inspection personnel. 6.2.2
3 Number of samples and judgment rules
JB/T7333-94
6.2.3.1 Three or three pairs (products used in pairs) of each product are taken for type inspection. One of them or one pair is qualified only after meeting the requirements of the test in Article 5.3.
If the requirements are not met after the test in Article 5.3, another sample should be taken to double the same test. All products tested in doubled test must pass 6.2.3.2
.
7 Usage requirements
7.1 When the angle of the lifting point of the lifting clamp used in pairs changes, the change of the rated lifting capacity shall be changed accordingly according to the provisions of Appendix A (Supplementary Part). 7.2 When the objects to be lifted are plates, they shall not be stacked for lifting. 7.3 The size of the weights lifted by various lifting clamps must be within the specified range. 7.4 During the use of the lifting clamp, the speed must be limited to the normal working range of the main machine. 7.5 The lifting clamp should be stopped when any of the following conditions occur: a. The deformation of the jaws reaches 5% of the original opening; The wear of the shaft reaches 5% of the original diameter; h.
The wear of the pliers shaft hole reaches 10% of the original size; c.
d. The wear of the teeth of the pliers tongue and jaw plate reaches 20% of the original tooth height; the bending deformation of the pliers shaft reaches 0.25% of the original length. e.
8 Marking, packaging, transportation and storage
8.1 Marking
8.1.1 The marking content should include:
Rated lifting capacity (t);
b. Product name, model, applicable range c. \mark or trademark;
d, manufacturing date and manufacturer's name.
8.1.2 Model and size of the suspended object should be permanently clear. 8.2 Packaging
Product packaging when leaving the factory should comply with the provisions of GB/T13384. 8.3 Transportation and storage
8.3.1 During transportation, load and unload lightly to avoid collision and rain. 2 During storage, the product should be prevented from rusting and paint falling off. 8.3.2
JB/T7333—94
|Appendix A
Relationship between the lifting point angle and the rated lifting capacity (supplement)
When the lifting point angle of the lifting clamp used in pairs changes, the rated lifting capacity of the lifting clamp should change accordingly (as shown in Figure A1 and Table A1). A1
Additional instructions:
Lifting point angle 0
This standard was proposed and coordinated by the Beijing Hoisting and Conveying Machinery Research Institute of the Ministry of Machinery Industry. This standard was drafted by the Beijing Hoisting and Conveying Machinery Research Institute. The main drafter of this standard: Hao Suoyun
Rated lifting capacity
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