100 Pcs/Pack, Head Diameter [7/16 in] *** Full Length top the bottom [5/8 in] *** Shank Length under the cap to bottom [1/2 in] Made by full automatic German machines with high quality steel and double layer electroplated Mat Black finish Strong and heavy weight items for upholstery industry, with proper tools you will not need any prefix hole. Please don't compare this items with filmsy cheap DIY nailheads. Requires proper tools like Needle nose pliers and light weight tack hammers to install them. Not using pliers will cause bending. So please don't use your fingers to hold them while hammering. You won't be disapointed, they will always stay bright & beautiful. Please don't use any chemicals to clean nailheads, it may damage the surface finish in time, so please just clean them with dry peace of cloth.