| 摘要 |
The method of fastening a plurality of metal members (82, 84; 232, 230) in which precision holes (86, 88; 236, 234) are drilled through the metals which are to be connected together. The drilled holes in the metal members are cold-expanded to improve the fatigue performance of the metal surrounding the hole and at the same time size the hole. Then a fastener (254) sized to make a desired fit is installed into the hole. The final hole diameters (236A, 234A) after expansion are equal to the starting hole diameters plus the retained expansions, there being spring back shrinkage of the expanded holes to the final hole diameter. The holes are sized by expanding them to at least a critical sizing expansion value which is a value of expansion beyond which the retained expansion value is linearly exceeded and to nearly the same amount as the total expansion before elongation of the hole axis of the metal surrounding the hole. This is a method of cold-expanding a series of holes to size in which the same tools are used, with the result that the holes are varied in the diameter no more than 0.001''.
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