Fluted sleeve standard on all models except 6200, 6206, 6204, 6208, 31138, which are smooth and ground , Jaws center-ground for absolute straightness and alignment , Jaws specially treated to ensure extended thread life and high gripping surface hardness , One-piece sleeve eliminates crack between driving teeth often found in other designs , Through-hardened sleeve teeth, nose, and keyholes for wear resistance , For portable, bench, or floor mounted power tools , At minimum capacity will hold a No, 60 (, 040in/1mm) drill SKU: ORSNO34445