Collection: Bolt-On Chuck Adapters

A bolt‑on lathe chuck adapter is a machined (or semi-machined) intermediary plate that lets you mount a larger lathe chuck onto a spindle designed for a smaller chuck. It bolts to the lathe spindle flange on one side, and to the chuck on the other.

SPINDLE FLANGE - Most mini lathes have an 80mm (3") spindle flange. HiTorque lathes usually have a 100mm (4") spindle flange. Our new 7600/7650 HiTorque Bench lathe has a 125mm (5") "locking" spindle flange.

REGISTRATION - All of our adapters are for Plain Back Chucks. Plain back chucks have standardized registration based on the size of the chuck. The correct adapter will have a registration recess (diameter) matching the spindle flange boss and a registration boss which matches the chuck's recess. Properly matching sizes ensures concentricity.

BOLT PATTERN - Similarly, plain back chucks generally have different bolt hole configurations depending on the type of chuck being mounted. 3 bolt holes (for a self-centering) or 4 holes (for independent) are used to secure the chuck to the adapter. A 6-hole spindle flange or adapter is designed to accommodate both types of chucks.

Make sure you are choosing the correct adapter for your chuck by confirming the specification outlined above and any other specifics related to your setup.

To help you get the right bolt-on lathe chuck adapter, we have a chart that provides the dimensions of bolt-on lathe chuck adapters that we sell. This page also has some "generic" bolt-on adapter plates, labeled as backplates in our product inventory. These backplates are flat adapters that are machined on the lathe side. The chuck side needs machining. Backplates are unthreaded. Visit Bolt on Lathe Chuck Adapter and Backplate Dimensions to view this reference data.