Scientific Cutting Tools’ 3/16" Diamond Insert Indexable Bars with coolant holes are ideal for precision boring in small-diameter applications. These bars feature a heat-treated steel head paired with a rigid micro grain carbide shank for dependable cutting performance. Internal coolant holes aid in chip evacuation and heat reduction, extending tool and insert life. Each bar includes one insert screw and one Torx key. Inserts are sold separately. Available with or without flats to suit your machine setup.