Allied Machine 21841-0004 Indexable Spade Drill 4MT Taper

Product Description

The ALLIED MACHINE AND ENGINEERING 21841-0004 is an indexable spade drill designed for high-performance metal removal in machining operations. It accepts interchangeable spade blade inserts and uses a 4MT taper shank with a shank diameter of 1.231 inches, making it compatible with standard Morse taper spindles and drill press setups. The drill covers a diameter range of 2 to 2-7/8 inches with a maximum drill depth of 9 inches. Through-coolant delivery via two radial entry ports keeps cutting temperatures controlled and helps clear chips from deep-hole applications. The overall length measures 15-9/16 inches. This tool is installed by machinists and toolroom technicians in production and job-shop environments.

This spade drill is suited for use on CNC machining centers, drill presses, and lathes equipped with 4MT taper toolholding. The HP-D series designation indicates a high-performance design rated for universal workpiece materials, including cast iron, steel, stainless, aluminum, and nonferrous alloys. The straight flute configuration provides clean chip evacuation and stable drilling geometry across the full 9-inch flute length. Radial coolant ports thread to 1/4 inch NPT and are compatible with the 2T-4SR rotary coolant adapter for pressurized through-coolant systems.

Key Features

• Diameter range of 2 to 2-7/8 inches accommodates multiple spade blade sizes within a single holder body
• Through-coolant design with 2-radial entry ports and 1/4 inch NPT coolant hole threads for chip flushing and heat control
• 4MT taper shank with 1.231-inch shank diameter fits standard Morse taper spindles
• Straight flute geometry with 9-inch flute length supports deep-hole drilling to 9 inches maximum depth
• Steel body construction in the HP-D series rated for high-performance cutting across universal workpiece materials
• Compatible with 2T-4SR rotary coolant adapter for pressurized coolant delivery

Compatibility

Rated for universal primary workpiece materials including cast iron, steel, stainless, aluminum, and nonferrous alloys (material codes K, M, N, P). Compatible with the 2T-4SR rotary coolant adapter. Designed for machines equipped with a 4MT taper spindle. Spade blade inserts are sold separately.

Installation Notes

Installation and tool changes must be performed by qualified machinists or toolroom personnel with the machine powered down and the spindle fully locked. Verify that the taper bore is clean and free of chips or burrs before seating the shank to ensure full contact and accurate runout. Coolant lines should be pressure-tested at the adapter connection before initiating a drilling cycle. Follow the machine manufacturer guidelines and applicable shop safety procedures when setting feeds and speeds for the selected workpiece material.