Ok guys, I’m using a lem stuffer , 1/2 inch OD tube, 21 mm collagen casing, I want to go to 19mm collagen casing, will casing fit over tube or am I into having a fight with it, (I’m having a brain failure, been metric since 63 now in US , everything is being quoted in mm or inches, but no definitive US/IMPERIAL / METRIC OD Direct conversion, manufacturers should put both dimensions on sites for tubes). Any help appreciated.I’m not going out to buy a micrometer for 1 use