ASME B18.29.2M:2005 pdf free download

ASME B18.29.2M:2005 pdf free download Helical Coil Screw Thread Inserts: Free Running and Screw Locking (Metric Series)
4 TERMINOLOGY Fordefinitionsofterms relatingto fasteners orcompo- nent features thereof used in this Standard, refer to ASME B18.12.
5 DIMENSIONS
(a) Unless otherwise stated, all dimensions in this Standard are in millimeters and apply before any coating. When plating or coating is specified, the finished product dimensions shall be as agreed upon by the sup- plier and purchaser.
(b) Symbols specifying geometric characteristics are in accordance with ASME Y14.5M.
6 DESCRIPTION Helical coil inserts are screw thread bushings coiled from wire of diamond-shape cross-section. Inserts are screwed into STI-tapped holes to form nominal size internal threads. Inserts are installed by torquing through a diametral tang. This tang is notched for removalafterinstallation. Inthe free state, theyarelarger in diameter than the tapped hole into which they are installed. In the assembly operation, the torque appliedto the tang reduces the diameter of the leading coil andpermits it to enter the tapped thread. The remainingcoils are reduced in diameter as they, in turn, are screwedinto the tapped hole. When the torque or rotation isstopped, the coils expand with a spring-like actionanchoring the insert in place against the tapped hole.
7 CLAss OF FIT
7.1 Tolerance Classes 4H5H and 5H
Since helical coil inserts are flexible, the class of fit ofthe final assembly is a function of the size of the tappedhole.Helical coil STI taps are available for both ToleranceClass 4H5H- (or Class 4H6H-) and Class 5Hl-tappedholes.Tolerance Class 5H-tapped holes provide maxi-mum production tolerances but result in lower lockingtorques when screw-locking inserts are used. The higherand more consistent torques given in Table 5 are metby the screw-locking inserts when assembled and testedin Tolerance Class 4H5H-(or Class 4H6H-) tapped holesin accordance with para.9.
7.2 Compatibility
Assembled helical coil inserts will mate properly withitems that have M Profile external threads in accordancewith ASME B1.13M.Also, due to the radius on the crestof the insert at the minor diameter, the assembled insertwill mate with MJ Profile externally threaded parts withcontrolled radius root threads per ASME B1.21M.
8TYPES OF INSERTS
8.1 Free-Running
The free-running insert provides a smooth, hard , andfree-running thread.
8.2 Screw-Locking
The screw-locking insert provides a resilient lockingthread produced by a series of chords on one or moreof the insert coils.
9STI-TAPPED HOLE
The tapped hole into which the insert is installed shallbe in accordance with ASME B1.13M, except that diame-ters are larger to accommodate the wire cross-section ofthe insert (see Fig-1).Dimensions of the STI-tapped holeare shown in Table 1 and are calculated per GeneralNote (c) to Table 1.
9.1 Screw Thread Designation
9.1.1 Designation for Tapped Hole.The drawing notefor the STI-threaded hole per Table 1 to accept the helicalcoil insert shall be in accordance with the followingexample:
EXAMPLE: M8 × 1.25-5H STI: 23.5 T per ASME B18.29.2M1.