ASME B18.29.2M-2005 pdf free download.Helical Coil Screw Thread Inserts: Free Running and Screw Locking (Metric Series).
11.1.2 Threads. The nserts, when assembled in STIthreaded holes conforming to Table I. shall form threads conforming to ASMI 111.1 3M Tolerance Class 4115)4 or 5H except for the locking feature of screw-locking inserts, The assembled insert, both types, shall accept and function with parts having external Mj threads per
NOTE The accuracy o( the finished thread when the inwr is installed dependois the accuracy o4 the lapped hole, lIthe Imished tapped hole gages satislactuelly. the Installed Iniert will be within the thread tolerance when 11w nwi1 meets the reqUirements 0411w 54andard. It i. therelore. nut necessary to gage the installed insett. Alter 11w insert is iiistalled, 11w GO thread plug gage may not enter freely because the insert may not have been fully seated an 11w tapped hole. However, the msert should become seated atier a bolt or screw is installed and tighteiwtL
11.1.3 Tang Removal Notch. The tang removal notch shall be located as shown in Fig. 2 and of such depth that the part may be installed without failure of the tang and that the tang m.w be removed, alter assembly, without affecting the function of the installed insert.
11.2 Self-LockIng Torque (Destructive)
The ttcww.Iocking insert, when assembled in threaded holes conforming to Table I and tested in accordance with th Following paragraphs, shall provide a frictional lock to retain the bolt threads within the to9uc limits specified in Table 5.
11.2.1 Torque Test Bolts. Assembled screw-locking inserts shall be torque tested with bolts in accordance with ASME BI.13M or ASME Bl.21M. cadmium pLated, or having other coating with a similar coefficient of friction and hardness of 36 [IRC to 44 FIRC, The bolts selected for this test shall Lie of sufficient length so the thread runout does not enter the insert and that a minimum of one full thread extends past the end of the insert when the bolt is fully seated, Acceptability of bolt threads shall be determined based on System 22 of
NOTE Until a rcplaccmcrit tor cadmium plating on the torque teat bolts (as specified in para. 11.2.1) is lound. and test data completed, an altemate coatingllubricanl can be used Ic’ perlorm the torque test (values may be different from those obtained ueing cadnuum-platad serews) based on agnrenwnt tietissen the custenser and tnwrt splIer
11.2.2 Torque Test Block and Spacer. The insert to be tested shall be installed in a Tolerance Class 4H5H— or 4H6H—threaded hole conforming to Table I in a test block made from 2024.T4 (SAE AMS4I2O or ASThI B 209M) aluminum alloy. After installation, the tang shall be removed. The surface of the test block from which the insert is assembled shall be marked 70P” and shall be marked to indicate the radial Location where the assembled insert begins. A steel spacer nieeting the requirements of Fig. 3 and Table 6 shall be used for developing the bolt load.
11.2.3 Torque Test Method. The torque test shall consist of a 15-cycle, room temperature test A new bolt or screw and new tapped hole shall be used for each completi’ 15-cycle test. Fur each of the 15 cycles. bolts shall he assembled and seated to the assembly torque specified inTable 5. Bolts shall be completely disengaged from the locking coils of the insert at the end of each cycle. The test shall be run at less than 40 rpm to yield a dependable measure of torque and avoid heating of the bolt.
11.2.4 MaxImum Locking Torque. Maximum locking torque shall be the highest torqUe value encountered on any installation or removal cycle and shall not exceed the values specified in Table 5. Maximum locking torque readings shall be taken on the first and seventh installation cycles before the assembly torque is applied and on the 15th removal cycle.