Method and apparatus for preloading a joint

A method for assembling a joint comprising a plurality of workpieces having aligned openings formed therein and a selectively reusable fastener assembly including a pin member having an enlarged head and a shank projecting therefrom formed with a threaded portion thereon, said method comprising:

• placing said shank of said pin member in said openings in said workpieces;
• placing a removable collar member having a deformable outer portion and a relatively hard inner portion including an inner surface, said inner portion being substantially undeformable in a radial direction, about a portion of said shank so that one end of said collar member is adjacent the outer surface of one of said workpieces;
• snugging the joint together to eliminate free play in the joint;
• deforming said outer portion of said collar member by the application of a radially inwardly directed force which displaces material in the outer portion of said collar member, the radially inward flow of displaced material being resisted by the hardened inner portion of said collar member whereby said displaced material in said outer portion flows axially elongating said collar member to induce a preload in said joint, said inner surface being spaced from said shank before and after deformation of said outer portion, whereby said collar member is removable from said pin member after deformation.