Patent ID: 7003862

Claim:
A method of assembly of at least two parts of an object with one another, comprising the steps of introducing a bolt having a thread into the parts so that a free end of the bolt extends outwardly beyond at least one side of the parts; placing a washer on the free end of the bolt; threadingly connecting a nut to the free end of the bolt so as to abut against the washer; placing a power tool so as to turn the nut with a rotatable element of the power tool connected to the nut to tighten or loosen the bolt and applying a non-rotatable element of the power tool to the washer to absorb a reaction force; and providing the body of the washer with a radially outer part having a first bearing face surface located at one axial side and adapted to cooperate with the nut and a second bearing face located at an opposite axial side and adapted to cooperate with the object, a radially inner part having at least one turning resistance surface, and a resistive point arranged so that when the nut is turned and turns the bolt said body of the washer stops the bolt from turning and thereby the nut creates a pull on the bolt which elongates the bolt in an axial direction and applies to said turning resistant surface an axial force which overcomes the at least one resistive points so that said radially outer part of said body does not move axially, while said radially inner part of said body of the washer with said turning resistant surface cooperating with the thread of the bolt is allowed to be pulled axially when the bolt elongates; and providing in said radial outer part an axial space, into which said radially inner part moves as it is pulled axially when the bolt elongates.