1/8 inch machinable hdpe panel for Swimming Pools-UHMW/HDPE Sheets 4×8 1/4 inch high density plastic sheet for Treads-HDPE sheets 4×. 1/4″ machinable high density plastic board supplier. Piedmont Plastics offers HDPE for cutting boards in three standard sheet sizes: 48” x 96”, 48” x 120”, and 60” x 120” in gauge sizes ranging