Twist drill bit set DeWalt DT4904-QZ, right-hand rotation, 2 pieces, blister pack

DeWalt DT4904-QZ twist drill bit set consists of two right-hand rotation bits supplied in a blister pack for general drilling tasks. Manufactured for drilling portable or stationary, these HSS-Co (high speed steel with 5% cobalt) twist drills are designed to cut metals with high alloy content and tensile strengths up to 1100 N/mm², including heat- and acid-proof steels, cast iron, bronze, welded seams, stainless and chrome-nickel steels. The set combines reinforced core construction, an optimised tip and flute geometry, and non-slip shanks to deliver improved penetration, chip evacuation and tool life for compatible drilling tools.

Advantages

The 5% cobalt content preserves a sharper cutting edge and provides substantially longer life compared with standard HSS-R bits. An optimised tip with a recessed cutting wing reduces burrs and aids cleaner, more accurate holes while a ‘no-walk’ tip facilitates initial penetration on surfaces 5 mm and above. Spin-proof three-sided shanks on applicable diameters improve grip in the chuck and reduce slipping during use. The thicker central core towards the chuck increases fracture stability during freehand drilling and the flute design accelerates chip removal and reduces heat build-up for faster drilling.

Suitable for

• Drilling high-alloy steels and stainless steels up to 1100 N/mm² tensile strength
• Working on cast iron, bronze and welded seams
• Portable and stationary drilling in metal fabrication and maintenance
• Applications requiring burr-reduced, accurate holes in metal

Key specifications

• Set contents: 2 twist drill bits in blister pack
• Rotation: right-hand
• Material: high speed steel with 5% cobalt (HSS-Co)
• Recommended workpiece tensile strength: up to 1100 N/mm²
• Features: no-walk tip, recessed cutting wings, optimised flute geometry
• Shank: three-sided, anti-slip design on applicable diameters
• Construction: reinforced central core increasing in thickness towards the chuck

How to use

Select the correct drill bit diameter for the required hole and secure it in the drill chuck, ensuring the anti-slip shank seats fully if applicable. Use right-hand rotation and an appropriate feed rate for the material. For hard, high-alloy steels and stainless materials, use steady pressure, adequate cooling or cutting fluid as appropriate, and avoid excessive speed to reduce wear and overheating. Start drilling with the no-walk tip to position the bit, then proceed with continuous rotary motion and allow the flutes to evacuate chips. Periodically withdraw the bit to clear chips and allow cooling during deeper or prolonged drilling operations.

Usage recommendations

For best results when drilling metals with high alloy content, use cutting fluid or coolant, secure the workpiece, and operate the drill at speeds and feed rates appropriate for HSS-Co bits. Inspect the bit regularly for wear and replace when the cutting edge degrades to maintain hole quality and reduce the risk of breakage.