Accupro 778894 BT40 JT33 Taper Adapter

Product Description

The ACCUPRO 778894 is a BT to Jacobs Taper adapter designed for use on CNC machining centers and manual milling machines equipped with BT40 spindles. It accepts a JT33 Jacobs Taper chuck on the inside connection and mounts to a BT40 spindle taper on the outside. The adapter provides a 1.18-inch projection and features a 15.85mm nose diameter. No coolant-through capability is included. This adapter is installed by machinists and toolroom technicians to allow Jacobs Taper drill chucks to be mounted directly in BT40 toolholding systems.

This adapter suits general-purpose drilling and light boring operations in job shops, production machining environments, and toolroom applications. It is compatible with standard BT40 spindle machines and JT33 Jacobs Taper drill chucks. Typical use involves mounting a keyless or keyed drill chuck for through-hole drilling operations on vertical machining centers with BT40 spindle interfaces.

Key Features

• BT40 outside taper connects directly to BT40 spindle toolholding systems
• JT33 inside taper accepts standard Jacobs Taper drill chucks
• 1.18-inch projection length for proper chuck clearance
• 15.85mm nose diameter for precise chuck seating
• No coolant-through passages, suited for dry or flood-external coolant operations

Compatibility

Designed as an OEM-style replacement and standard toolholding adapter for BT40 spindle machines requiring a JT33 Jacobs Taper chuck interface.

Installation Notes

Installation is performed by a machinist or toolroom technician. Ensure the spindle is fully powered down and locked out before changing toolholders. Seat the BT40 taper fully into the spindle and torque the retention knob to the machine manufacturer specification. Inspect the JT33 taper bore for chips or burrs before mounting the chuck to ensure proper seating and runout performance.