Rather quixotic interview process. At first it was very accommodating; they found my résumé on Monster.com and reached out via a phone interview, then offered to bring me to their Aurora, OH facility for a series of interviews. They paid for my flight, hotel and rental car, and were generally extremely nice and helpful.
The interviews themselves were exhaustive. I got a tour of the facility, spoke with several former or current management trainees, and a couple of people in midlevel management. I got the sense that they were trying to get a read on my personality more than they were trying to get answers to specific questions. The first sit-down interview focused on my senior thesis and went off into long digressions, with more of the atmosphere of an intellectual conversation, for example. Other interviews focused on management techniques or my previous jobs. Almost all of the interviewers seemed to be intelligent and good at their jobs. I left feeling satisfied that, whether I got the job or not, I'd taken a lot of notes and done my best.
Here's where it gets sketchy. They said they'd contact me within two weeks. My interview was on a Friday, and on the following Tuesday, they sent out a form letter saying that my skills were not a match for the position (well, if they weren't, why did you bring me in for an interview at all?). I didn't get that letter, through no fault of McMaster-Carr's, for about three weeks. However, when I contacted the hiring manager at the end of the two-week period to inquire about whether a decision had been made, she told me that it had yet to be made and that I should wait another week! Needless to say, when I got the letter and realized that the hiring manager had at best purposely misled me, I was not pleased. The same person who had called me in the first place sent the letter and answered my emails, so it's hard to credit a communications breakdown for what happened.
Upshot: great facility, smart people, inconsiderate hiring practices.