CMT Reduction Ring for Saw Blades - 1" x 7/8" (25.4mm x 22.2mm) by CMT is a precision-machined arbor adapter bushing designed to reduce a saw blade's bore from a 1-inch (25.4mm) outer diameter down to a 22.2mm inner bore. This circular saw blade bushing gives woodworkers and tradespeople a simple, reliable way to fit blades with a larger arbor hole onto saws with a smaller arbor - eliminating the need to purchase additional blades just to match a different machine's spindle size. Available in multiple sizes, this arbor adapter ring is a practical solution for table saws, miter saws, and stationary saws where arbor hole compatibility is needed.

Key Features

• Outer Diameter - 1 inch (25.4mm): Matches the bore of saw blades with a 1-inch arbor hole - allowing you to use those blades on machines or arbors sized for smaller spindles without modification.
• Inner Bore - 22.2mm (7/8 inch): Reduces the arbor opening to 22.2mm, providing a snug, concentric fit on 7/8-inch arbors so your blade runs true and without wobble.
• Maximum Thickness - 0.055 inch (approx. 1.4mm): A thinner profile compared to other reduction ring variants, meaning it seats cleanly in the blade's arbor recess without interfering with clamping hardware or blade guards.
• Adjustable arbor hole compatibility: Designed specifically as a saw blade reducing bushing, it adapts the arbor hole of circular saw blades, table saw blades, and miter saw blades - one ring, broad usability across your shop.
• Available in different sizes: Part of a full family of saw blade arbor adapter ring sizes from CMT, so you can match the exact outer-to-inner diameter reduction your setup requires.
• Purpose-built for saw blade arbor reduction: Engineered to reduce arbor size precisely - not a makeshift solution - giving you confidence that your blade is centered and secure during every cut.

Why This Product

• If you own a saw blade with a 1-inch bore but your table saw or miter saw has a 7/8-inch (22.2mm) arbor, this reduction ring solves the mismatch directly - no new blade purchase required, no risky improvisation.
• The 0.055-inch maximum thickness keeps the ring low-profile inside the arbor recess, so it works with standard blade clamping flanges and does not add problematic height between the blade and the arbor flange.
• CMT offers this reduction ring in multiple outer-to-inner diameter combinations, meaning once you find the right size for one machine, you can source the correct ring for other saws in your shop from the same trusted product line.
• Designed explicitly for circular saw blade arbor reduction, this bushing provides a precision fit that keeps the blade centered on the spindle - supporting clean, accurate cuts on stationary table saws, miter saws, and similar machines.

Specifications

• Manufacturer Part Number: 299.239.00
• Brand: CMT Orange Tools
• Outer Diameter: 1 in. (25.4mm)
• Small Diameter: 22.2mm
• Bore Diameter: 22.22mm
• Maximum Thickness: 0.055 in.
• Application: Reduction ring for saw blades

Approved Applications

• Arbor hole reduction for circular saw blades
• Fitting saw blades to table saws with a smaller arbor spindle
• Fitting saw blades to miter saws with a smaller arbor spindle
• Stationary saw arbor adapter applications

Frequently Asked Questions

What size does this reduction ring adapt from and to?

This ring fits into a saw blade with a 1-inch (25.4mm) arbor bore and reduces it down to a 22.2mm (7/8-inch) inner bore, so the blade can be mounted on a machine with a 7/8-inch arbor spindle.

How thick is the CMT 299.239.00 reduction ring?

The maximum thickness is 0.055 inches. This thinner profile is designed to seat cleanly within the arbor recess of the blade without interfering with the arbor flange or clamping hardware.

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

This arbor adapter bushing is designed for use with circular saw blades, table saw blades, and miter saw blades. It is intended for use on stationary table saws, miter saws, and similar machines where the arbor is sized at 22.2mm (7/8 inch).

Is this reduction ring available in other sizes?

Yes. CMT offers this saw blade arbor adapter ring in different sizes to cover various outer-to-inner diameter reduction requirements. The 299.239.00 specifically handles the 1-inch outer to 22.2mm inner configuration.