The CMT 299.217.00 Reduction Ring from CMT is a precision-machined saw blade arbor adapter bushing designed to reduce a 5/8 in. outer diameter arbor hole down to a 1/2 in. (12.7mm) inner bore, giving woodworkers and tradespeople the flexibility to mount blades with smaller arbor holes on machines with larger arbor shafts. This circular saw blade bushing is an essential accessory for anyone working with mismatched blade and arbor sizes, eliminating the need to purchase entirely new blades simply because of a bore size difference.

Key Features

• Outer diameter of 5/8 in. (15.87mm) - fits standard saw arbor sizes used on table saws, miter saws, and circular saws, ensuring broad machine compatibility
• Inner bore of 12.7mm (1/2 in.) - provides a precise reduced fit so blades with smaller arbor holes seat securely and run true without wobble
• Maximum thickness of 0.047 in. - the slim profile keeps the ring low-profile so it does not interfere with blade seating depth or saw function
• Adjustable arbor hole compatibility - allows a single blade to be adapted to multiple machines, reducing tool inventory costs and expanding blade versatility
• Available in different saw blade arbor adapter ring sizes - choose the exact reduction increment needed for your specific blade and machine pairing

Why This Product

• Solves the common mismatch problem between saw blade arbor holes and machine arbor shafts, letting you use your existing blade inventory on a wider range of saws without purchasing duplicate blades
• The slim 0.047 in. maximum thickness is engineered specifically for saw blade use, meaning it does not add unwanted height or alter blade geometry during cutting operations
• Designed to reduce from 5/8 in. to 1/2 in. - one of the most frequently needed arbor reduction increments in woodworking and general construction environments
• CMT offers this reduction ring in multiple sizes, so as your tool collection grows, you can continue using a consistent, trusted adapter solution across different arbor configurations

Specifications

• Manufacturer Part Number: 299.217.00
• Brand: CMT Orange Tools
• Outer Diameter: 5/8 in. (15.87mm)
• Small Diameter: 12.7mm
• Diameter Bore: 12.7mm
• Maximum Thickness: 0.047 in.

Approved Applications

• Reduction rings for saw blades - adapts blade arbor holes to match machine arbor shaft sizes
• Arbor size reduction for table saws, miter saws, and circular saws
• Adjustable arbor hole adaptation for circular saw blades

Frequently Asked Questions

What does this reduction ring do?

This CMT reduction ring is a saw blade arbor adapter bushing that reduces the arbor opening of a saw blade from a 5/8 in. (15.87mm) outer diameter down to a 1/2 in. (12.7mm) inner bore. It allows you to mount a blade with a 1/2 in. arbor hole onto a saw with a 5/8 in. arbor shaft, bridging the gap between mismatched blade and machine bore sizes.

What types of saws is this reduction ring compatible with?

This circular saw blade bushing is designed for use with saw blades on machines such as table saws, miter saws, and circular saws - any machine where the arbor shaft size does not match the bore size of your saw blade.

How thick is this arbor adapter ring, and will it affect blade performance?

The maximum thickness of this reduction ring is 0.047 in. This slim profile is intentionally designed for saw blade applications, keeping the adapter low-profile so it does not interfere with blade seating or alter cutting performance.

Is this the only size available in the CMT reduction ring series?

No - CMT offers this type of saw blade arbor adapter ring in different sizes to accommodate a range of arbor reduction requirements. The 299.217.00 specifically handles the 5/8 in. to 1/2 in. (12.7mm) reduction, but other sizes are available in the CMT reduction ring lineup for different bore combinations.