Abstract: A thin-walled hollow body open at one end, e.g. a metal can body (76), is given a terminal neck (74) by engaging a primary chuck nose (22) sealingly in the open end and pressurizing the body internally to pre-stress it and hold it against a lift pad (16); the latter is lowered so that the sidewall end portion (80) is progressively rolled by forming rolls (46) to form the neck partly in free space (38) and partly against a secondary chuck nose (30) which maintains the pressure seal when the seal between the sidewall and the primary chuck nose is broken. In a modification, the rolls (46) may be withdrawn early, so as to leave a terminal flange on the can body.

Abstract: A method of forming a smooth shoulder (16, 14b, 19b), neck (17, 37) and flange (18, 38) at the open end of the cylindrical side wall (12) of a can body (10) comprises the steps of forcing a marginal edge portion (13) of the side wall into at least a first die to form a first portion of reduced diameter having a first shoulder portion (14) and a first cylindrical portion (15); and optionally applying at least one rolling operation to the first portion of reduced diameter, and any further die formed portions of reduced diameter subsequently formed, to generate a smooth shoulder (16, 14, 19b), neck (17, 37) and flange (18, 38). Reference is made to the roll forming process described and claimed in British Pat. No. 1,534,716 as being particularly suitable. The margin-portion (13) is preferably thicker than the rest of the side wall (12).