In some ways McMaster and Grainger compete. Such as huge variety of products, in stock and ready to ship ASAP.
Where they don't compete is price. Grainger's pricing seem to be based on the concept that you need it NOW and are willing to pay whatever it costs. McMaster's pricing is competitive with other vendors. The only thing I dislike about McMaster is that you don't know what brand product you are getting. In most cases they don't tell you, reminds me of the JC Whitney catalog of years gone by. I will say that I have been pleased with the quality of nearly every product I have got over the years. Twice I got something I deemed inferior and they made it right immediately. One time stating that it was the 2nd complaint on a tool and that a new vendor would supply that Torx driver in the future.
Grainger for what its worth has slipped in the recent years. They closed the local branch here in MN and they now rely on overnight shipping or couriers from larger stores. I'm sure this makes a lot of sense financially but seeing as I have to ship an item then there are a LOT of other providers that beat then on price. A few years ago we had a big contactor burn up in our air compressor. A machine shop can't do much without air. With the local Grainger branch having the part in stock, I ran to pick it up while a coworker pulled the old one out. I handed him the new relay right about when he was ready for it. Total time without air was actually less then 30 minutes! The relay was about 50% higher in cost compared to other vendors but well worth it from a downtime standpoint. Without the immediate part-in-hand of the local branch I don't use Grainger much anymore.
