Precision Twist Drill 5998351 No. 28 9/64 Hss Drill Bit

Product Description

The PRECISION TWIST DRILL 5998351 is a jobber-length drill bit designed for general-purpose drilling in a wide range of metallic and hard materials. Built from high-speed steel with a steam oxide coating, it carries a 118-degree standard point angle and a web-thinned, tapered web configuration that reduces entry force and improves chip clearance. The straight-cylindrical shank measures 9/64 inch (0.1405 inch decimal) in diameter, and the overall length is 2.875 inches with a 1.75-inch flute length. The two-spiral-flute, right-hand-cut geometry follows ANSI standards and is suited for production or maintenance drilling where consistent hole quality is required.

This bit is intended for use on steel, stainless steel, cast iron, non-ferrous metals, superalloys, titanium, and other hard materials. It fits standard drill chucks in handheld drills, drill presses, and CNC machining centers. The Series R18 designation places it within Precision Twist Drill's R10-R15-R18 family of general-purpose jobber bits. At a flute-to-diameter ratio of 12xD and a maximum drilling depth of 1.75 inches, it is well suited for through-hole and blind-hole applications in light to medium production environments as well as field service work.

Key Features

• High-speed steel construction with steam oxide finish for improved lubricity and corrosion resistance
• 118-degree standard point angle for general-purpose entry on ferrous and non-ferrous materials
• Web-thinned, tapered web reduces thrust load and improves chip evacuation
• Right-hand cut, regular spiral, two-flute design for balanced chip removal
• Straight-cylindrical shank fits standard three-jaw drill chucks without adapters
• ANSI-compliant geometry; Series R10-R15-R18 family

Compatibility

Designed as an ANSI-standard jobber-length drill bit compatible with any drill chuck accepting a straight-cylindrical shank of 9/64 inch (0.1405 inch) diameter, including handheld power drills, bench drill presses, and CNC spindles configured for general-purpose drilling.

Installation Notes

Installation and use should be performed by machinists, maintenance technicians, or qualified tradespeople familiar with rotating cutting tools. Secure the shank firmly in a properly sized chuck before operation and confirm chuck runout is within acceptable limits to prevent bit deflection or breakage. Coolant-through is not supported on this bit; apply cutting fluid externally when drilling steel or stainless steel to extend tool life. Wear appropriate eye protection and follow applicable shop-safety and machine-guarding requirements during all drilling operations.