Trend 2214/38WS Plug maker match 3/8 inch diameter Clean cut plug makers for timberPrecision made plug makers for use on natural timber, exactly matching the holes produced by the Saw Tooth Forstners groups 1306 & 1307.These have four to six wings to ensure a clean cut. Use a slow, constant feed rate ensuring timber is clamped to bed of drilling machine. Do not use these tools on abrasive timber or hard plastics or metal. Not suitable for use with a router. Not for use with hand held power tools or routers.Specification-D=3/8 inchD=9.5 mmOL=139.7 mmShank Dia=1/2 inchShank lng.=50.8 mm