The cup head pin is a insulation fastener which is used for fasten the insulation to the sheet metal of insulation construction. It works with a welding machine,Website:http://www.insulationpin.net, through welding for fasten the insulation.The washer are made of 0.4mm thickness sheet metal, the pin can be in 12GA or 14GA, the plating can be galvanized or cooper plated. When washer with a kratf paper, it will provide protection when weld through foil faced insulation, when pin with plastic sleeve, it will provide protection when weld through tin faced insulationMaterialStandard material: Low Carbon steel, Stainless steelPlating Pin-Galvanized coating or cooper platingWasher: Galvanized coating SizeWasher: 1-3/16" 1-1/2"Pin diameter: 12GA(2.7mm) 14GA(2.0mm)Length3/8" 5/8" 7/8" 1" 1-1/8" 1-3/8" 1-5/8" 1-7/8" 2" 2-1/8" 2-3/8" 2-7/8" 3" etcAccept customization for other lengthsApplication1: Position insulation 2: Press cup head pin through insulation3: Weld in place to complete installation