An automatic machine for assembling and banding together the components making up an expansion shell so that the assembly can be conveniently packaged and shipped. In one embodiment, the machine contains a series of work stations arranged to assemble the bolt components within a die. The expansion shell halves are staked to a common strap and the components then passed through a combination forming gage and banding mechanism which aligns the parts in assembly and bands them together using a plastic sleeve. In a second embodiment of the invention, the expansion shells are staked to the strap prior to being loaded into the die.