It also doesn't ship world wide, even to Canada I made an order, with no way to see what shipping was and got an email saying they only ship to commercial or schools. That's a terrible e-commerce experience. Sites like NCIX were way better than this.
10+ years ago they used to ship to individuals in Canada, but I vaguely remember some negative word-of-mouth discussions about them when individuals got burned by "customs fees" which was actually companies like UPS ripping off people by charging unreasonable fees to do customs clearance paperwork. Mcmaster probably didn't want to deal with that.
If they do think you're a business (maybe this means someone at your business has ordered before), they will not only ship to you but instantly let you use net-30 payment terms automatically. I had one experience of ordering some parts to a university in Japan when I was a student, and the parts were shipped the same day, along with an invoice. I didn't even have to create a login. [0]
[0] I wouldn't be surprised if this is no longer true due to know-your-customer legislation.