14 Piece 3.0-16.0mm Disc Cutter Set ~ Punches are made of case-hardened tool steel. ~ The top and bottom plates are made of durable shock-resistant tool steel through hardened for long-wear. ~ Round disc cutters let you cut perfectly round discs in up to 1mm (18 gauge) thick metal sheets. ~ Slide metal between the plates and, with a mallet or heavy hammer of your choice, hit once for best results. ~ Set includes 3.0, 4.5, 5.0, 6.0, 7.0, 7.5, 8.0, 8.5, 10.0, 11.0, 12.0, 13.0, 14.0 & 16.0mm disc sizes.