Jacobs 31416 Keyless Drill Chuck 5/8 in R8 Integral Shank

Product Description

The JACOBS 31416 is a keyless drill chuck designed for use with R8 integral shank milling machines and drill presses. It accepts drill bits and tooling from 7/64 inch (0.118 inch) up to 5/8 inch (0.630 inch) capacity, covering the full range of common drilling operations in a machine shop environment. The keyless design allows for fast, tool-free bit changes without a chuck key. Constructed from steel with a ball bearing mechanism, the 31416 delivers consistent grip and smooth rotation up to 4000 RPM. The sleeve diameter measures 2.13 inches, and closed length is 3.78 inches. Machinists and tool room technicians are the primary installers.

The JACOBS 31416 is suited for light to medium-duty drilling in vertical milling machines and drill presses equipped with an R8 taper spindle. The integral shank mount provides a direct, rigid connection to the spindle without an adapter. This chuck is appropriate for production shops, job shops, and maintenance facilities where quick tooling changes and reliable runout control are priorities. The 0.0016 inch TIR rating supports accurate hole placement across standard drilling operations.

Key Features

• Keyless operation for fast bit changes without a chuck key
• Capacity range: 7/64 inch to 5/8 inch (0.118 to 0.630 inch decimal)
• R8 integral shank mount for direct spindle connection
• Ball bearing construction for smooth, consistent chuck rotation
• TIR of 0.0016 inch for accurate hole placement
• Rated to 4000 RPM maximum spindle speed
• Steel chuck body for durability under repeated use

Compatibility

Designed for use with vertical milling machines and drill presses equipped with an R8 taper spindle accepting an integral shank drill chuck.

Installation Notes

Installation should be performed by a qualified machinist or tool room technician. Power down and lock out the machine before mounting or removing the chuck from the spindle. Ensure the R8 taper and chuck shank are clean and free of chips or burrs before seating. Draw bar torque should follow the machine manufacturer's specification - do not over-torque, as this can damage the spindle taper.