36.4.2 Machined Test Specimens: If the size and shape of the bolt Is such that a stress-rupture test cannot be made on the bolt, a test specimen prepared as in 4.5.8, maintained at 1100 °F ± 3 °F while a load sufficient to pioduce an initial stress of 140 ksi is applied continuously, shall not rupture in less than 23 hours. Tests shall be conducted in accordance with ASTM E 139. Specimens may be required by purchaser to perform confirmatory tests.
36.5 Fatigue Strength: Finished tensicrn bolts tested in tension-tension fatigue at room temperature with maximum load as specified in Table 2 and minimum load equal to 10% of Itie maximum load shall have an average life of not less than 65,000 cycles with no part having life less than 45.000 cycles. Tests need not be run beyond 130,000 cycles. Life of parts which do not fail in less than 130,000 cycles shall be taken as 130,000 cycles for purposes of computing average life. If the shank diameter of the bolt is less than the minimum pitch diameter of thread, bolts shall withstand fatigue testing as above using loads sufficient to produce a maximum stress of 135 ksi and a minimum stress of 13.5 ksi. The above requirements apply to tension bolts, such as double hexagon and spline drive heads per design parameters spedfled in MS21296. 0.190 inch and larger in nominal thread size, having a head-to-shank fillet radius equal to or larger than that specified in MS2 1296, and not having an undercut: for all parts to which the above requirements do not apply, fatigue test requirements shall be as specified on the part drawlng
3.6.6 Ultimate Shear Strength: Finished parts having a close toleranced full shank as in MS21296 shall have an ultimate double shear load no lower than that speclfied in Table 2. The double shear test may be discontinued without a complete shear failure after the ultimate double shear load has been reached, first measuring and recording the maximum double shear load achieved. Shear bolts having special shank diameters shall have the minimum ultimate double shear load based on 132 ksi minimum shear strength, Shear tests are not required for the following conditions:
a. Bolts threaded to head.
b. Protruding head bolts having coarse toleranced full shank.
c. Protruding head bolts having PD or relieved shank.
3.7 Quality:
Parts shall be uniform in quality and condition, free from burrs (tight burrs may be acceptable if part performance is not affected), foreign materials, and from imperfections detrimental to the usage of the parts.
3.7.1 Macroscopic Examination, Headed Blanks: A specimen cut from a headed blank shall be etched in a suitable etchant and examined at a magnification of 20X to determine conformance to the requirements of 3,7.1.1 and 3,7.1.2. The head and shank section shall extend not less than D2 from the bearing surface of the head, where D equals the nominal diameter after heading.