Complete your deck project and expand your family's living space with the unobtrusive look of the FastenMaster Tiger Claw TC-120 Hidden Fastener system. The ideal choice for grooved hardwood decking material, the Tiger Claw TC-120 fastener features prongs that embed themselves into the upper section of the routered out boardside for strong holding power that's invisible from above the decking. Crafted from corrosion-resistant Grade 304 stainless steel, the Tiger Claw TC-120 clips are approved for use in saltwater and coastal applications as well as ACQ rated for chemically treated lumber. Delivering a steady deck board spacing of 1/8 inch to 3/16 inch, the TC-120 hidden deck fastener reduces wood splitting, rot and water-damage, and board cupping.