Mich. Admin. Code R. 408.12723
Rule 2723. A hand fed circular rip saw shall have a spreader to prevent material from squeezing the saw or being thrown back at the operator. The spreader shall be made of steel, or its equivalent, and shall be thinner than the saw kerf and slightly thicker than the saw disk. It shall be at least 1 inch wide at the table to provide adequate stiffness or rigidity to resist any reasonable side thrust or blow tending to bend or throw it out of position. The spreader shall be attached so it will remain in true alignment with the saw even when either the saw or table is tilted. It should be placed so there is not more than 1/2 inch space between the spreader and the back of the saw when the largest saw is mounted in the machine. If a blade smaller than maximum permissible size is used, the spreader shall be moved to within 1/2 inch of the blade. A spreader need not be used in connection with grooving, dadoing or rabbeting. On the completion of such operations, the spreader shall be replaced immediately.
Mich. Admin. Code R. 408.12723