Michigan Compiled Laws, Chapter 211. Taxation of Real and Personal Property § 211.9b

(a) “Product” means an item of tangible property that is directly created or produced through the manufacturing process. A product may be any of the following items:

(b) “Special tool” means a finished or unfinished device such as a die, jig, fixture, mold, pattern, special gauge, or similar device, that is used, or is being prepared for use, to manufacture a product and that cannot be used to manufacture another product without substantial modification of the device. The length of the economic life of the product manufactured shall not be considered in making a determination whether a device used to manufacture that product is a special tool. Special tools do not include the following:

(c) “Standard tool” means a die, jig, fixture, mold, pattern, gauge, or other tool that is not a special tool. Standard tool does not include machinery or equipment, even if customized, and even if used in conjunction with special tools or standard tools.