Our 5/16" Right-Hand Triangle Insert Indexable Boring Bars with Coolant Holes are designed for high-efficiency internal machining in limited spaces. Each bar combines a precision-ground carbide shank with a hardened steel head, delivering superior rigidity and wear resistance. The through-coolant channel directs fluid to the cutting edge, improving chip evacuation and extending tool life—especially critical in blind-hole or deep-bore applications. Compatible with triangle-style inserts, these tools are ideal for machinists requiring accuracy, reliability, and thermal control in small-diameter boring operations.