ASME B18.29.1:2010 pdf free download.Helical Coil Screw Thread lnserts- Free Running and Screw Locking (lnch Series).
1.4 Class of Fit
Since helical coil inserts are flexible, the class of fit of the final assembly is a function of the size of the tapped hole. Helical coil STI taps are available for both tolerance Classes 2B and 3B tapped holes. Tolerance Class 28 tapped holes provide maxim urn production tolerances, hut result in lower locking torques when screw locking inserts are used. The higher and more consistent torques given in Table 5 are met by the screw locking inserts when assembled and tested in tolerance Class 3B tapped holes in accordance with section 2.
1.5 Compatibility
Assembled helical coil inserts will mate properly with items having UN external threads in accordance with ASME 81.1. In addition, due to the radius on the crest of the insert at the minor diameter, the assembled insert will mate with UNI profile external threaded parts with controlled radius root threads per SAE AS8879.
1.6 Types of Inserts
1.6.1 Free•Running. The free-running insert provides a smooth, hard, and free-running thread.
1.6.2 Screw-Locking. The screw-locking insert provides a resilient locking thread produced by a series of chords on one or more of the insert coils.
2 STI TAPPED HOLE
The tapped hole into which the insert is installed shall be in accordance with ASME Bl.1, except that diameters are larger to accommodate the wire cross-section of the insert. Dimensions of the STI tapped holes are shown in Table I and calculated per Note (3) of Table 1.
2.1 Screw Thread Designation
2.1.1 Designation for Tapped Hole. The drawing note for the STI threaded hole per Fable I to accept the helical coil insert shall be in accordance with the following example:
EXAMPLE: UNC-28 Sn thread 0.430 mm. depth. per ASME B18.29.1.
2.1.2 Designation for a Helical Coil Insert. DesignaHon of the helical coil insert on parts lists, spares lists, purchase orders, etc., shall be in accordance with the following examples:
EXAMPLES:
(1) ASME H18.29.1. -20 UNC 0.375 long helical coil free-running insert.
(2) ASME B18.29.1, #10-32 UNF 0.380 king helical coil screw-locking insert.
2.1.3 Designation for STI Threaded Hole Including Installed Helical Coil Insert.
2.2 Gages and Gaging
Acceptance of the threaded hole is determined bygaging with sTIGO,NOTGO (HI), and plain cylindricalgages designed and applied in accordance withSystem 21of ASMEB1.3 (see NonmandatoryAppendix C).
3HELICAL COIL INSERT3.1 Insert Material
Chemical composition of the inserts is austenitic cor-rosion resistant(stainless) steel within the limits of Table 2.
ASME B18.29.1:2010 pdf free download
