As a part of our differential chuck range we have 9mm wide differential chucks that are suitable down to a slit width of 10mm. The overall cost of differential shafts will rise slightly the smaller your minimum slit width. The 9mm wide diff chucks aren't especially expensive, you just need more of them if you're slitting the full width of the shaft. Some customers use a variety of chuck widths (and / or spacers) on their shafts then have the operators move the chucks around according to which job is being run, this takes time, so other customers load their entire shafts with narrower width chucks. The logic being that the initial cost of the chucks is quickly mitigated by the saved labour and time costs. Wide rolls will run on narrow differential chucks without any issue, whereas narrow slit rolls will not wind happily onto wide differential chucks. So is it worth investing in narrow differential chucks? The answer is yes!
Personal blog of a Slitter salesman.