Allied Machine 21641-0004 Indexable Spade Drill 2-2-7/8in

Product Description

The ALLIED MACHINE AND ENGINEERING 21641-0004 is an indexable spade drill designed for high-performance hole-making in a wide range of workpiece materials. Built on the HP-D Series platform, it accepts interchangeable spade drill inserts and delivers consistent bore diameters from 2 inches to 2-7/8 inches. The 4MT taper shank mounts directly into compatible machine spindles, and the through-coolant design with radial entry ports channels cutting fluid to the tip to manage heat and chip evacuation. At 11-1/16 inches overall length with a 4-1/2 inch flute length, this is a short-length configuration suited for rigid setups on machining centers, lathes, and horizontal boring mills.

This drill is intended for metalworking operations in production and job-shop environments where large-diameter drilling is required without the cost of a solid carbide tool. The universal workpiece material rating covers steels, cast irons, non-ferrous alloys, and non-metallic materials, making it a versatile holder for general production. The 4MT taper shank is a standard interface found on many manual and CNC machine tools. Installation and setup are performed by machinists and toolroom technicians. The 1/4 inch NPT coolant port thread allows connection to standard through-spindle or rotary coolant adapters, including the 2T-4SR rotary adapter.

Key Features

• Drill diameter range: 2 inches to 2-7/8 inches via indexable spade inserts
• Maximum drill depth: 4-1/2 inches (short-length classification)
• 4MT taper shank with 1.2310 inch shank diameter for direct spindle mounting
• Through-coolant system with 2-radial entry ports and 1/4 inch NPT coolant hole thread
• Straight flute geometry for chip clearance in through-coolant drilling applications
• Compatible with 2T-4SR rotary coolant adapter for live-spindle coolant delivery
• Steel body construction; HP-D Series high-performance platform

Compatibility

Designed for use with indexable spade drill inserts in the HP-D Series. Compatible with the 2T-4SR rotary coolant adapter. Rated for universal primary workpiece material codes K, M, N, and P, covering cast iron, non-ferrous, non-metallic, and steel material groups.

Installation Notes

Installation is performed by a qualified machinist or toolroom technician. Ensure the machine spindle taper bore is clean and free of chips or burrs before seating the 4MT shank. Confirm the coolant supply pressure and flow rate are appropriate for the NPT port size before engaging through-coolant. Follow the machine tool manufacturer torque and drawbar specifications for taper-shank retention.