Precision Twist Drill 5998959 Drill Bit 0.358 in Hss

Product Description

The PRECISION TWIST DRILL 5998959 is a screw machine length drill bit designed for high-performance metal removal in demanding shop and field applications. Manufactured from high speed steel with a bright uncoated finish, it measures 0.358 inches (Letter T) in diameter and delivers a 118-degree standard point angle with web thinning for reduced thrust on entry. At 3-1/16 inches overall length with a 1-3/4-inch flute length, this stub-style bit fits applications where clearance is limited and rigidity is a priority. A licensed machinist, tool-and-die technician, or HVAC fabrication tech would be the typical installer.

The 5998959 is suited for drilling through titanium and similar high-strength materials in both production and maintenance environments. The Series R42 designation indicates a high-performance general-purpose bit built to ANSI standards. The 2.5xD flute-to-diameter ratio and tapered web configuration support chip evacuation in deeper holes without sacrificing core strength. Right-hand spiral flute geometry keeps cutting action predictable across ferrous and non-ferrous stock.

Key Features

• 0.358-inch (Letter T) diameter, screw machine length for improved rigidity in tight clearances
• High speed steel construction rated for titanium and general-purpose metalworking
• 118-degree standard point angle with web thinning to reduce entry thrust
• Tapered web and 2.5xD flute ratio for efficient chip evacuation
• Bright uncoated finish — inspect and resharpen with standard grinding equipment
• Straight cylindrical shank fits standard drill chucks without adapters
• Built to ANSI specifications, Series R42

Compatibility

Designed as an OEM-style replacement or direct addition to any standard drill chuck accepting a straight cylindrical shank in the 0.350 to 0.400-inch diameter range, per ANSI Series R42 screw machine length specifications.

Installation Notes

Installation is performed by machinists or fabrication technicians using a drill press, CNC machining center, or hand-held drill motor with a properly rated chuck. Secure the shank fully in the chuck and verify runout before drilling. When cutting titanium or high-strength alloys, use appropriate cutting fluid to manage heat buildup and extend tool life. Never exceed the rated speed range for the workpiece material and bit diameter.