ISO 15872-2017 pdf free download

ISO 15872-2017 pdf free download.Aerospace UNJ threads Gauging Aéronautique et espace — Filetage UN] — Verification par calibres.
6.1.1 Virtual pitch diameter indicating thread gauges
6.1.1.1 It measures, on two or three segments or rolls, the maximum material virtual pitch diameter taking into account variations of form such as pitch variation, helix and flank variations, roundness and taper which produces an enlargement of the virtual pitch diameter. In addition, virtual pitch diameter control ensures the flank angle contact is sufficient to ensure that the root radius does not exceed the maximum limit. Measurement of virtual pitch diameter with indicating gauges shall be obtained to calculate virtual minus simple pitch diameter differential unless the simple pitch diameter limits, gauged in accordance with 6.1.3. are within the limits defined by the maximum pitch diameter and the form variation limits in ISO 3161.
6.1.1.2 Indicating gauges have two or three contacts at 1800 or 120°, respectively. Gauges with segments or rolls are designed with the length of the GO virtual maximum material gauging elements equal to the GO ring gauge length equal to nine pitches (P) or the basic major diameter of the thread, whichever is the smallest. For configuration and profile requirements, see Figure 1.
6.1.1.3 The minor diameter of the GO virtual maximum material thread segments and the diameter of the circle surrounded by the roll cluster of GO virtual maximum material rolls shall be equal to the pitch diameter of the product minus 0.375H. less the Tp1 value in Table 2 minus tolerance when assembled in the gauge frame. This corresponds to a flat width of 0,312 SPun the minor crest for the thread. The crest shall be flat in an axial plane and parallel to the axis of the segments or rolls.
6.1.1.4 The major diameter of the GO virtual maximum material segments and the root of the GO virtual maximum material rolls shall be cleared beyond a 0,125P flat either by an extension of the flanks of the thread toward a sharp vee or by an undercut no greater than 0,125P maximum width and approximately central. The root clearance shall be such that the major diameter of the full form section of the thread setting plug gauge is cleared after the assembled gauge has been properly set to size.
6.1.15 The pitch diameter cylinder axis of threaded segments and rolls shall be straight within the diameter tolerance zone equal to Tp1 specified in Table 2. The half-angle variations in the segment or roll thread shall be within the limits specified in Table 3. For the pitch variations, see Table 4.
6.1.2 Solid or adjustable GO screw ring gauges
To ensure the ease of assembly of product threads and conformance to the maximum material virtual pitch diameter limits, solid or adjustable. GO screw ring gauges with thread form in accordance with Figure 1 and setting gauges in accordance with ZLI may be used. Solid GO screw ring gauges shall not be permitted to exceed the product thread dimensional limits, The gauge thickness/length shall be standardized (see 6.1A.2). Details on adjustable GO thread ring gauges and truncated setting plugs may be obtained from ASME B 1.2.ISO 15872-2017 pdf free download.