CMT Reduction Ring for Saw Blades - 7/8" x 20mm by CMT is a precision-machined arbor adapter bushing designed to reduce a 7/8 inch (22.2mm) outer diameter bore down to a 20mm inner bore, allowing circular saw blades with a 20mm arbor hole to mount securely on machines with a larger arbor. Whether you are adapting a table saw blade, miter saw blade, or another circular blade to a different arbor size, this saw blade arbor adapter ring provides an adjustable, snug fit that keeps your blade centered and running true.

Key Features

• Outer diameter of 7/8 inch (22.2mm) with a 20mm inner bore - precisely bridges the gap between a larger machine arbor and a 20mm blade hole, giving you accurate, wobble-free blade mounting
• Maximum thickness of 0.055 inch - a slim profile that fits within the blade seat without creating interference or altering blade height on the arbor
• Designed to reduce the arbor size of saw blades - lets you use a wider selection of circular saw blades on machines with differing arbor dimensions, expanding blade compatibility
• Available in different saw blade arbor adapter ring sizes - part of a product family that covers multiple arbor reduction combinations, making it easy to find the right fit for your specific machine and blade pairing
• Adjustable arbor hole compatibility - the circular saw blade bushing accommodates the arbor hole so your blade seats correctly without modifications to the blade or the machine

Why This Product

• Solves the common arbor mismatch problem - when a saw blade's 20mm bore does not match a machine arbor sized at 7/8 inch (22.2mm), this reduction ring closes that gap instantly without replacing the blade or the machine spindle
• Compact 0.055 inch maximum thickness keeps the adapter from adding unwanted height or play to the blade stack, helping maintain precise cutting geometry on stationary table saws and miter saws
• Part of CMT's range of reduction rings offered in multiple sizes, so if you work with blades of varying bore sizes across different machines, you can standardize on a single brand of adapters for consistent, reliable performance
• A straightforward, low-cost solution for circular saw blade compatibility - rather than purchasing a new blade to match your arbor, this bushing lets you use the blade you already have on a machine with a different spindle size

Specifications

• Manufacturer Part Number: 299.238.00
• Brand: CMT Orange Tools
• Outer Diameter: 7/8 inch (22.2mm)
• Small Diameter: 20mm
• Bore Diameter: 20mm
• Maximum Thickness: 0.055 inch

Approved Applications

• Reduction rings for saw blades
• Arbor size reduction for circular saw blades
• Adjustable arbor hole adaptation for circular saw blades

Frequently Asked Questions

What does this reduction ring do?

This CMT reduction ring serves as an arbor adapter bushing that reduces a 7/8 inch (22.2mm) outer diameter arbor bore down to a 20mm inner bore. It allows you to mount a circular saw blade with a 20mm arbor hole onto a machine that has a 7/8 inch (22.2mm) arbor, filling the gap so the blade sits securely and concentrically on the spindle.

What is the maximum thickness of this reduction ring?

The maximum thickness of the CMT 299.238.00 reduction ring is 0.055 inch. This slim profile is designed so the bushing fits within the blade seat without adding excessive height or creating clearance issues between the blade and the arbor flange.

What types of saw blades and machines is this bushing compatible with?

This saw blade reducing bushing is designed for use with circular saw blades, including table saw blades and miter saw blades, on machines where the arbor size needs to be reduced to accommodate a 20mm blade bore. It is suited for applications on stationary table saws, miter saws, and similar circular blade equipment.

Does CMT offer this reduction ring in other sizes?

Yes. The CMT 299.238.00 is part of a family of reduction rings available in different saw blade arbor adapter ring sizes. If your blade and machine combination requires a different outer or inner diameter, CMT offers additional reduction ring options to cover other arbor reduction pairings.