Jacobs 31415 Keyless Drill Chuck 5/8 in 4MT Taper Shank

Product Description

The JACOBS 31415 is a keyless drill chuck designed for heavy-duty drilling applications on machine tools equipped with a No. 4 Morse taper (4MT) spindle. The chuck accepts drill shanks and tooling from 7/64 inch (0.118 inch) up to 5/8 inch (0.630 inch), covering the full range of standard twist drills, end mills with straight shanks, and other round-shank tooling commonly used in production and maintenance machining. The keyless design allows for fast, hand-tightened tool changes without a chuck key. Ball bearing construction supports smooth rotation up to 4000 RPM. The sleeve diameter is 2.13 inches and closed length is 3.78 inches. Machinists, tool-and-die technicians, and maintenance trades install this chuck on drill presses, lathes, and milling machines.

The JACOBS 31415 is suited for both job-shop and industrial maintenance environments where a reliable, repeatable 4MT taper chuck is needed. The integral shank mount seats directly into a No. 4 Morse taper spindle bore, eliminating the need for a separate arbor. Typical applications include production drilling on floor-model drill presses, quill-mounted setups on knee mills, and tailstock use on engine lathes where a 4MT taper is standard. The steel chuck body handles the radial and axial loads generated by moderate-to-heavy drilling and reaming cycles. Total indicated runout (TIR) of 0.0016 inch supports accurate hole placement and clean entry cuts.

Key Features

• Keyless operation for fast tool changes without a chuck key
• Capacity range from 7/64 inch to 5/8 inch for broad tooling compatibility
• No. 4 Morse taper integral shank mounts directly to 4MT spindle bores
• Ball bearing construction rated to 4000 RPM
• TIR of 0.0016 inch for accurate, repeatable chuck runout
• Steel chuck body for durability under production drilling loads
• Sleeve diameter of 2.13 inches and closed length of 3.78 inches

Compatibility

Designed for machine tool spindles with a No. 4 Morse taper (4MT) bore, including drill presses, engine lathes, and milling machines that use an integral shank taper mount without a separate arbor.

Installation Notes

Installation is performed by machinists or qualified maintenance technicians. Before mounting, power down and lock out the machine spindle per OSHA lockout/tagout procedures. Clean the 4MT spindle bore and chuck shank thoroughly to remove oil, chips, and debris before seating the taper to ensure full contact and accurate runout. Drive the chuck shank firmly into the spindle bore with a soft-faced mallet; do not use a steel hammer directly on the chuck body. To remove, use the appropriate drift and knockout bar for 4MT tapers.