This standard specifies the lifting eye nuts with thread specifications of M8~M100×6. This standard is applicable to general loading and unloading of lifting machinery and equipment. JB/T 7382-1994 Lifting eye nuts JB/T7382-1994 Standard download decompression password: www.bzxz.net
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1994-07-26 Issued Eye nut Ministry of Machinery Industry of the People's Republic of China JB/T7382-1994 1995-07-01 Implementation Standard of Machinery Industry of the People's Republic of China Eye nutwww.bzxz.net 1 Subject content and scope of application This standard specifies the eye nut with thread specification of M8~M100×6. This standard is applicable to general loading and unloading of lifting machinery and appliances. Note: Commercial fastener varieties should be preferred. :Referenced standards GB1237 GB5267 GB6394 Fastener acceptance inspection, marking and packaging Basic dimensions of common threads ((diameter 1~600mm)Tolerance and fit of common threads (diameter 1~355mm)Metal Rockwell hardness test method Technical conditions for high-quality carbon structural steel Marking method for fasteners Electroplating layer of threaded fasteners Method for determination of average grain size of metal 3 Type, size and maximum lifting weight 3.1 Type and size shall be as specified in Figure 1 and Table 1. (d,) Approved by the Ministry of Machinery Industry on July 26, 1994 Standard Download Network (www.bzxzw.com) JB/T 73821994 1995-07-01 implementation Thread specification , (reference) Maximum lifting weight shall be in accordance with the provisions of Table 2 Thread specification D Marking method shall be in accordance with GB1237. Marking example JB/T73821994 M72×6 Marking of eye nut with thread specification of 20mm, material of 20 steel, normalized and without surface treatment: mm M10 0×6 M80M100 JB/T73821994 3.2 The maximum lifting weight shall be in accordance with the provisions of Table 2. Thread specification D 4 Marking 4.1 The marking method shall be in accordance with the provisions of GB1237. 4.2 Marking example JB/T7382-1994 M56M64 Marking of eye nuts with thread specification of 20mm, material of 20 steel, normalized and without surface treatment: nut JB/T7382 M20 5 Technical conditions 5.1 Technical requirements 5.1.1 The eye nut should be made of 20 or 25 steel (GB699). M72 M80M100 5.1.2 The eye nut must be forged as a whole. The forgings should be normalized and the oxide scale should be removed. The grain size of the finished product should not be lower than the 5th grade specified in GB6394 5.1.3 The allowable displacement and residual burr of the forgings shall be in accordance with Table 3. Table 3 Thread specifications Allowable misalignment Allowable residual burr M8~M20 The perpendicularity tolerance t of the thread axis to the support surface shall be in accordance with the provisions of Table 4. Table 4 Thread specification D Thread specification D M24~M48 M72×6 M56~M100×6 M80×6 M100×6 JB/T7382-1994 5.1.5 Forgings shall not have forging defects such as overburning and cracks. 5.1.6 The basic dimensions of the thread shall be in accordance with GB196, and the tolerance shall be in accordance with the 7H grade of GB197. 5.1.7 Mechanical properties 5.1.7.1 The eye nut shall be subjected to an axial proof load test, and the load shall be in accordance with the provisions of Table 5. No cracks are allowed after the test, and the deformation rate of the permanent deformation of the ring shall not be greater than 0.5% Thread specification D Axial guaranteed load Thread specification D Axial guaranteed load 5.1.7.2 The eye nut shall be subjected to hardness test, and its hardness value shall meet 67~95HRB. Surface treatment M72×6 M80×6 M100×6 The eye nut is generally not subjected to surface treatment. According to the use requirements, surface treatments such as zinc plating purification and chrome plating can be carried out, and shall be in accordance with GB5267. Hydrogen embrittlement treatment shall be carried out immediately after electrogalvanizing. 5.2 Test method The chemical composition and mechanical property tests of materials shall be in accordance with GB699. 5.2.2 The test method of grain size shall be in accordance with GB6394. 5.2.3 Thread inspection is carried out with thread gauge and smooth limit gauge or universal tool. 5.2.4 Axial proof load test 5.2.4.1 The gauge length Io of the test device and the ring of the eye nut is shown in Figure 2. te Support ladder ($.5D) Hardness 48~52HRC Thread ladder core Hardness 48~52HRC Thread 6g JB/T 73821994 5.2.4.2 Before loading, measure the gauge length lo with a vernier caliper, load to the axial proof load value specified in Table 4 and keep it for 15s, measure the gauge length value 1 after unloading, and calculate the deformation rate according to the following formula. Deformation rate = -), 5.2.5 Hardness test is in accordance with the provisions of GB230. 5.3 Acceptance inspection, marking and packaging ×100% 5.3.1 The material grade (20 or 25) mark and the manufacturer's trademark or identification should be made at the position shown in Figure 1. 5.3.2 During the acceptance inspection, the main dimensional items and qualified quality levels are: thread go gauge and stop gauge inspection according to AQL=1.0; other minor dimensional items are all according to AQL=2.5. Mechanical property spot check items are: axial proof load, hardness and grain size inspection. Other requirements for acceptance inspection, marking and packaging shall be in accordance with GB90. 5.3.3 JB/T73821994 Requirements for the use of eye nuts (Supplement) The maximum lifting weight of eye nuts is only applicable to the eye nuts of this standard with bolts (columns) with 8g tolerance, and the minimum thread length of the bolts (columns) is 0.8D. When overloaded, in order to avoid nut failure, the tensile strength of the bolt (column) is not allowed to exceed 500N/mm2. A2 The eye nut must fit tightly with the support surface, but it is not allowed to be tightened with tools. No load perpendicular to the plane of the eye is allowed. When the "double nut lifting" method in Table 2 is adopted, it should be ensured that the two eye planes are in the same plane. When the "double nut lifting" method in Table 2 is adopted, the angle of the steel cable should not be greater than 90°. The single piece weight of the eye nut shall be as specified in Table A1. Table A1 Thread specifications Single piece weight Thread specifications Single piece weight Additional instructions: This standard is proposed and managed by the National Technical Committee for Standardization of Fasteners. M64 M72×6 M80×6 M100×6 This standard was drafted by the Machinery Standardization Research Institute of the Ministry of Machinery Industry, with participation from Tianjin University and Shengfang Standard Parts Factory. 6 People's Republic of China Mechanical Industry Standard Eye nut JB/T73821994 Published and issued by the Mechanical Science Research Institute Printed by the Mechanical Science Research Institute (No. 2 Shouti South Road, Beijing Format 880×1230 Postal Code 100044) Sheet 5/8 Word count 12,000 First edition in March 1995 First printing in March 1995 Price 6.00 yuan Print run 1-500 Mechanical Industry Standard Service Network: http://www.JB.ac.cn68 Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.