1、 ENGINEERING STANDARDS Test Procedure SUPERCEDED EDS-T-7148 Method of Prevailing Torque Test for Nut This standard may be applied only for current projects. It is Superceded for all future projects and replaced by USCAR-10. “8 88x 7 , F6* 72T8p) F$ . 1.1 +95 . ., E:48t 8% =72P % 95 8 )Y8x -O# :07d#.
2、E7 =%L6 E*8p) 8F , 1$4 = .E8 d# 148x -:Fd 88F 17%L# ) “07 38%P E:48x 957F$ . 2.1 17 E:4 / . DIN 267 Part15 ISO 898/2 ISO 2320 2.2 GM E:4 / . None 2.3 dA E:4 / . None GM KOREA ENGINEERING STANDARDS EDS-T-7148 Copyright 2011 General Motors Company All Rights Reserved July 2011 Page 2 of 8 Version : 3
3、3 Resources 3.1 Equipment. 3.1.1 Torque Measuring Device. The accuracy of a torque wrench or power device shall be within 2 % of the maximum of torque of the device. 3.1.2 Load Measuring Device. 3.1.2.1 A load measuring device shall be capable of measuring the tensile load induced when the nut is ti
4、ghtened with the test bolt. 3.1.2.2 The accuracy of the measuring device shall be within 5 % of the test clamp load measured. 3.1.3 Test Bolt. 3.1.3.1 The bolts which the nominal diameter of threads is 24 mm maximum shall be produced by rolling. 3.1.3.2 Bolt length shall be such that a minimum lengt
5、h equivalent to 4 to 7 thread pitches from the end of the bolt will protrude through the nut when the nut is seated against the test washer. 3.1.3.3 Thread length shall be such that a minimum of two thread pitches are within the grip after the nut is seated. 3.1.3.4 The thread surface shall be free
6、from burrs and bursts. 3.1.3.5 The hardness of the bolt shall be HRC 35 min. 3.2 Test Piece. 3.2.1 For the test piece, the products(lock nut) as it is shall be used. 3.2.2 The number of test pieces shall be 3 or more at least, for the first approval 1 or more at least for the routine quality control
7、 4 Procedures 4.1 Conditions. 4.1.1 Test Conditions. Deviations from the requirements of this standard shall have been agreed upon. Such requirements shall be specified on component drawings, test certificates, reports, etc. 4.2 Instructions. Test methods are classified into method A which is carri
8、ed out in the routine quality control of lots and method B, the one extended from A, which is performed in the approval of the products. 4.2.1 Method A. 4.2.1.1 The test shall be performed at room temperature using a torque wrench and a clamp load measuring device. 4.2.1.2 A test bolt shall be inser
9、ted in the load measuring device, and then the nut shall be assembled on the bolt as shown in Figure 1. 3 4G 88 3.1 4G 8/x . 3.1.1 B7XA ?U9I 8? . B7XA )? D# D88? (Power Device)8 9I-4$# 8/x8 $4 B7XA 8 2 % -88 !7 866 F$ . 3.1.2 F:E ?U9I8? . 3.1.2.1 F:E ?U9I8?# 4G 7 .0C) “2F 2Fp? 81 =%L6 866 F$ . 3.1.3.4 .0C8 !1. E+7# - (Burr), Bd; , E* MAX 0.80 :0 1: I$ . 10, Gl? M87 Fp?4 1.258 7 E 1,27 &d( d8F$ .
