CMT Reduction Ring for Saw Blades - 30mm Outer Diameter x 5/8" (15.88mm) Bore by CMT is a precision-machined arbor adapter bushing designed to fit saw blades with a 30mm bore onto machines with a 5/8-inch arbor. This circular saw blade bushing makes it possible to use a wider range of blades on stationary table saws, miter saws, and circular saws - expanding your blade compatibility without requiring new tooling or equipment. Available in a variety of arbor adapter ring sizes, the CMT saw blade reducing bushing is a practical, accurate-fitting solution for woodworkers and contractors who work with blades sourced from different arbor standards.

Key Features

• 30mm outer diameter with a 15.88mm (5/8") inner bore - adapts metric-bore saw blades to standard 5/8-inch arbor machines, so you can use more blades with the equipment you already own.
• Maximum thickness of 0.055" - a slim profile ensures the ring seats properly within the arbor recess without interfering with blade seating or clamping.
• Designed specifically to reduce the arbor size of saw blades - engineered for the precision fit required by rotating cutting tools, reducing vibration and promoting stable, wobble-free operation.
• Available in different saw blade arbor adapter ring sizes - the CMT reduction ring line offers multiple configurations so you can match a variety of bore-to-arbor combinations across your blade inventory.
• Adjustable arbor hole compatibility - the bushing design accommodates the circular saw blade's bore, giving you flexibility when swapping blades between machines with different arbor standards.

Why This Product

• Solves the mismatch between 30mm bore blades and 5/8-inch arbor machines - instead of replacing a blade or a saw, this small adapter ring bridges the gap and puts your existing equipment back to work immediately.
• Precision tolerances in the 30mm-to-15.88mm reduction keep the blade centered on the arbor - a poorly fitting bushing can cause runout and unsafe blade wobble, making an accurately machined ring like this a safety-relevant upgrade.
• Part of a broader range of CMT arbor adapter ring sizes - if you work with multiple blades and multiple machines, you can standardize on CMT reduction rings across your shop rather than sourcing mismatched adapters from different suppliers.
• Compact 0.055" maximum thickness - the low-profile design fits without adding meaningful stack height to the arbor assembly, keeping clamping geometry correct for table saw blades, miter saw blades, and circular saw blades alike.

Specifications

• Manufacturer Part Number: 299.211.00
• Brand: CMT Orange Tools
• Outer Diameter: 30mm
• Small Diameter (Inner Bore): 15.88mm (5/8")
• Maximum Thickness: 0.055"

Approved Applications

• Reduction rings for saw blades - adapting metric bore blades to smaller arbor machines
• Compatible with table saw blades, miter saw blades, and circular saw blades
• Use with stationary table saws, miter saws, and circular saws equipped with a 5/8-inch arbor

Frequently Asked Questions

What does this reduction ring do, exactly?

This CMT saw blade reducing bushing fits inside the bore of a saw blade that has a 30mm hole, reducing the effective bore down to 15.88mm (5/8") so the blade can be mounted on a machine with a 5/8-inch arbor. It lets you use metric-bore blades on equipment with a standard 5/8-inch spindle.

What is the maximum thickness of this reduction ring?

The maximum thickness is 0.055". This slim profile is intentional - it allows the ring to seat inside the blade's bore and fit flush against the arbor flange without adding significant stack height to the assembly.

Will this ring work on a table saw, a miter saw, and a circular saw?

Yes. This circular saw blade bushing is suitable for use with table saw blades, miter saw blades, and circular saw blades, as long as the machine has a 5/8-inch arbor and the blade has a 30mm bore. Always confirm your machine's arbor size and your blade's bore before fitting any reduction ring.

Is this the only size CMT offers in its reduction ring line?

No. CMT offers reduction rings in different saw blade arbor adapter ring sizes to cover a range of bore-to-arbor combinations. If 30mm x 5/8" does not match your specific blade and machine pairing, check the other available sizes in the CMT 299 series.