GBD 4-1/2" (114MM) 180SC FLEX-HONEThe GBD41218 FLEX-HONE® tool for surface finishing and deburring is designed for bore sizes between 4.251" and 4.500". Featuring 6.00" of abrasive globules which are composed of 180 grit Silicon Carbide (SC). Excellent for Mild steel, stainless steel, cast iron and other softer ferrous materials. 180 grit generally provides an Ra Finish range of 30 - 40 Microinch (.7 - 1 Micrometer).