[daniel_reetz]

I spoke to a McMaster web team member at a bar. They told me that the real reason there's usually no brand information is that they buy the same bolt (for example) from many different suppliers to guarantee availability.

They will only put a brand on a product (example: 3M DP420) when it truly comes from a single source and has special meaning/implications.

That said, I order tens of thousands of dollars of McMaster Carr items each year. They almost always come in packages from the OEM with OEM part numbers. So if I want more bolts like that, I just look at the box they were delivered in. The info is just not on the web interface.