WARNING Tire Companies: Some rack manufacturer's ship different racks than the tire racks they quote to their customers.
All major tire companies use tire racks to store their tires. Since this is a very common item purchased by tire companies, many steel manufacturer's try to sell stack racks. Unfortunately, tire racks have very low margins. Companies that manufacture these racks must be very efficient. Many companies find out right away, they can't produce these racks to make a profit. 
Sadly, these companies quote customers a rack that weighs 150#, but ship customers a rack that weighs 125#. Since steel is sold by the pound, this could reduce the rack cost by 10-20%. Many tire companies are now receiving racks that don't meet the requirements for seismic loads or every day use. For this reason, Tier-Rack strongly recommends you weigh your racks. Then check to make sure that it matches your quoted weight. Also, checking the gauges of all the tubes is very helpful to make sure you get what you paid for.
In conclusion, there are many "Used Car Salesmen" in the tire rack industry. For your companies safety and well being, please make sure you receive the product that was quoted to your company, after all you paid for it.
To learn more about tire racks click www.tier-rack.com, email sales@tier-rack.com, or call 1-800-325-7869 for more information.