Somewhat informal. Discussed desired position and pay, past experience in the trade, and answered questions about work and education history, etc. Required to pass certain weld tests if applying to be a craftsman. I was given a welder in the far corner of the shop, and told to set it up for 6g carbon pipe test. I cut my own test coupons, fit the pieces together, and had a quality department employee verify that it was correct. Then I took the weld test over the next few hours, cut the coupons myself, and had the quality department verify that I had passed. The hiring manager then offered me the job, and we discussed a starting date.

Interview process was pretty easy. They gave me a print test, a weld test, and then the interview. Everything takes a couple of hours. I got the job the same day.