What types of equipment are 601 fuses used surrounded by? what other applications?
You need to be more descriptive over what you mean by 601. My guess is that you are discussion about surface mount size 0601 which is a Jedec standard dimension describing the dimension (in metric) of the attacment pads. This does not own anything to do with the power rating or trip point or trip speed of a fuse, which are the typical ways to rate the performance of a fuse for a extraordinary appplication. Although 0601 is a rather small package for a fuse and plainly is a lower current trip point device.