VEVOR Bun Pan Rack, 20-Tier Commercial Bakery Racks with Brake Wheels, Aluminum Racking Trolley Storage for Half & Full Sheet, Speed Rack For Kitchen Home, Bread Baking Equipment, 26"L x 20.4"W x 70"H

Approximately, the U washers are M8, and the hex bolts are M8 × 38 mm.

No, pans are not included. The VEVOR Bun Pan Rack includes only the aluminum rack trolley structure and its four wheels; you must supply your own half- or full-size sheet pans.

Yes, its wheels can be locked in place. The product description states that it comes with two rear brake wheels, allowing you to roll it around or lock it in place.

e) Are its dimensions suitable for storing under standard commercial ovens?

The product description states that this bun pan rack is suitable for commercial kitchen use. It is designed for bakeries, restaurants, and catering services.