Michigan Compiled Laws, Chapter 570. Liens § 570.542

(a) “Customer” means a person who causes a special tool builder to design, develop, manufacture, assemble for sale, or otherwise make a special tool for use in the design, development, manufacture, assembly, or fabrication of metal parts, or a person who causes an end user to use a special tool to design, develop, manufacture, assemble, or fabricate a metal product.

(b) “End user” means a person who uses a special tool as part of his or her manufacturing process.

(c) “Special tool” means any tools, dies, jigs, gauges, gauging fixtures, special machinery, cutting tools, or metal castings manufactured by a special tool builder.

(d) “Special tool builder” means a person who designs, develops, manufactures, or assembles special tools for sale.

(e) “Person” means an individual, firm, partnership, association, corporation, limited liability company, or other legal entity.