The Irwin HSS Pro Drill Bit manufactured from high quality HSS steel. They have precision ground cutting edges for fast drilling and perfect finishing, a ground flute for maximum accuracy and fast chip removal and a universal 118 point shape for drilling a wide selection of materials. The Irwin IRW10502286 HSS Pro Drillbits comes in a bulk pack of 10. Specifications:Drillbit diameter: 5.5mmTotal length: 93mmWorking Length: 57mm IRWIN Hss Pro Drill Bits Bulk Pack (10) 5.5Mm Ol:93Mm Wl:57Mm in Silver