Sumitomo U101143 Carbide Screw Machine Drill Bit 0.368 in

Product Description

The SUMITOMO U101143 is a solid carbide screw machine length drill bit designed for high-performance drilling in demanding metalworking applications. Sized at 0.368 inches (Letter U) in diameter with a 135-degree split point, it delivers fast chip evacuation and accurate starts without a center punch. The two-flute, straight-cylindrical shank design fits standard drill chucks and CNC machining centers. Coolant-through capability supports high-speed drilling cycles where heat buildup is a concern. This bit belongs to the MDW-HGS series and carries a tapered web configuration with two margins for superior hole straightness and finish quality.

This drill bit is suited for production environments and job-shop operations where consistent hole quality in ferrous materials is required. Primary workpiece materials include cast iron, stainless steel, and steel. The screw machine length format provides a rigid, compact geometry that reduces deflection in short-reach drilling setups on lathes, mills, and drill presses. A flute-to-diameter ratio of 3xD and a maximum drilling depth of 1.318 inches make it appropriate for through-holes and shallow blind holes in structural and machined components.

Key Features

• Solid carbide construction for extended tool life in ferrous and abrasive materials
• 135-degree split point reduces thrust force and eliminates walk on entry
• Coolant-through design supports chip flushing and thermal control at high feed rates
• Screw machine length (overall 4.173 inches) provides rigidity and minimizes deflection
• Tapered web with two margins delivers consistent hole geometry and finish
• Diameter tolerance h8 ensures precise fit for close-tolerance hole applications

Compatibility

Designed for use in standard straight-shank drill chucks and collet holders on CNC machining centers, lathes, and drill presses. Suitable for drilling cast iron, stainless steel, and steel workpieces within the 0.350 to 0.400 inch drill bit size range per the MDW-HGS series.

Installation Notes

Installation and tool changes should be performed by a qualified machinist with the machine powered down and locked out per applicable safety procedures. Verify chuck or collet runout before seating the shank to protect the h8 diameter tolerance and prevent premature edge wear. When using coolant-through capability, confirm coolant pressure and flow rate are within the machine spindle specifications before initiating a cutting cycle. Do not exceed the maximum drilling depth of 1.318 inches in a single pass without confirming chip clearance.