Precision Twist Drill 5996359 Letter L Hss Jobber Drill

Product Description

The PRECISION TWIST DRILL 5996359 is a Letter L jobber-length drill bit machined from high speed steel with a bronze coating and a 135-degree split-point tip. It cuts a 0.290-inch diameter hole and delivers a 4.25-inch overall length with a 2.9375-inch flute length, making it a practical choice for through-hole and intermediate-depth drilling operations. The 135-degree point reduces the tendency to walk on entry, which matters when working on harder alloys without a center punch. The web-thinned, tapered-web construction reduces thrust load at the tip. Two right-hand spiral flutes evacuate chips efficiently during the cut.

This drill bit is suited for production and maintenance drilling in steel, stainless steel, cast iron, superalloys, and titanium. It fits standard three-jaw drill chucks via its 0.290-inch straight cylindrical shank with no flats. The general-purpose tool performance rating covers a broad range of shop, field, and service applications where a reliable Letter L size is needed. Licensed HVAC technicians, plumbers, electricians, and millwrights routinely reach for a jobber-length bit in this size range when drilling through sheet metal, pipe hangers, unistrut, or structural steel during installation work.

Key Features

• Letter L size: 0.290-inch cutting diameter per ANSI specification
• 135-degree split point reduces walking on hard and work-hardened materials
• Web-thinned, tapered-web geometry lowers thrust and extends tip life
• Bronze-coated high speed steel for increased surface hardness and chip flow
• Right-hand cut with regular spiral and two flutes for consistent chip evacuation
• Straight cylindrical shank fits standard chucks with no adapter required

Compatibility

Part of the PRECISION TWIST DRILL HX10-HX15-HX18 series. Designed for use in steel, stainless steel, cast iron, superalloys, and titanium workpieces. Fits any standard three-jaw or keyless drill chuck accepting a 0.290-inch straight shank.

Installation Notes

Install in a properly rated drill press, hand drill, or right-angle drill before energizing the tool. Secure the workpiece and confirm the chuck is fully tightened before starting the cut. Apply cutting fluid when drilling stainless steel, titanium, or superalloys to manage heat and extend bit life. Inspect the point for chipping or heel wear before reuse; a dull 135-degree point on hard material will work-harden the bore wall and shorten subsequent bit life.