How is a flat-file cabinet different from a plan chest?

The terms are used interchangeably in most commercial contexts. "Plan chest" is a term more commonly used in the UK and in woodworking or art contexts; "flat-file cabinet" or "map cabinet" is the more common commercial term in North America. Both refer to wide, shallow-drawer storage for oversized flat documents. At OfficeFurniture2go.com, we use "flat-file cabinet" as the standard term and carry commercial-grade products in both steel and wood — call 1-800-460-0858.