W 670 radial engine installing crush washers Stearman biplane SD 480p

crush washers are not torqued, they are tightened by degrees determined by the number of threads per in and metal type from a chart. On a W 670 continental 220 radial engine with a 16 threads per inch inspection bolt, the rotation is 135 degrees after hand tightening.

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Thank you. Helpful information.