Western Digital was founded on April 23, 1970 as General Digital, initially (and briefly) a manufacturer of MOS semiconductor test equipment. It rapidly became a specialty semiconductor maker, with startup capital provided by several individual investors and industrial giant Emerson Electric Company. In July, 1971, they adopted their current name, had moved to Newport Beach, California, and soon after introduced their first product, the WD1402A UART. Western Digital is currently the second largest hard drive company, after Seagate Technology.

WD’s model number format simplifies inventory management for distributors and system manufacturers. Capacity points are key to this format.

Base Model Number

The base model number is composed of six codes:

1. Company initials (WD)
2. Capacity (GB/TB)
3. Capacity unit/form factor

4. Business unit/brand
5. RPM/buffer size or attribute
6. Interface/connector



Download the detailed document here about the Western Digital Model Numbers