The CMT 551-168X Bi-Metal Plus Hole Saw delivers professional-grade performance in a 6-5/8 in. (168mm) diameter cutting tool engineered for demanding metalworking and multi-material applications. Built with an 8% Cobalt bi-metal (BIM) construction, this hole saw provides twice the cutting life of standard bi-metal saws, making it the right choice for contractors and tradespeople who cut stainless steel, steel, cast iron, aluminum, copper, brass, and plastics on a regular basis. The right-hand rotation and variable 4-6 TPI tooth configuration allow for efficient chip clearance and smooth cutting across a wide range of workpiece materials, reducing heat buildup and extending blade life on tough jobs.

Key Features

• 8% Cobalt Bi-Metal (BIM) Construction - the elevated cobalt content in the tooth alloy delivers 2x longer cutting life compared to standard hole saws, meaning fewer blade changes and lower cost per hole on steel, stainless steel, and hardened materials.
• 6-5/8 in. (168mm) Cutting Diameter - a large-format hole saw sized for electrical conduit penetrations, HVAC knockouts, pipe pass-throughs, and similar large-diameter boring tasks where precision matters.
• 45mm Cutting Depth - provides sufficient depth capacity to bore through thick-gauge metal panels, structural steel sections, and multi-layer material stacks in a single pass.
• Variable 4-6 TPI Tooth Pitch with Alternate and Side-Set Geometry - the variable pitch reduces vibration and chatter during cutting, while the alternate and side-set tooth profile produces a cleaner kerf and faster material removal across both ferrous and non-ferrous metals.
• XTREME FAST Push and Lock System - tool-free arbor changes in under 3 seconds keep downtime minimal on the job site, compatible with the 550-PH85 (11/32 in. hex) and 550-PH11 (7/16 in. hex) Push and Lock arbors.
• Right-Hand Rotation - optimized for use with standard cordless drills, corded drills, and drill presses without the need for special tooling or adapters.
• Made in Italy - manufactured to CMT precision standards for consistent dimensional accuracy and tooth geometry across the full 551 Series.

Why This Product

• Professionals cutting stainless steel, cast iron, or hardened steel regularly will see a measurable reduction in blade replacement frequency thanks to the 8% Cobalt BIM tooth construction - a direct cost and time savings on high-volume projects.
• At 6-5/8 in. (168mm), this hole saw handles large-diameter penetrations for conduit, pipe, and HVAC applications that smaller standard-size saws simply cannot reach - one tool for jobs that would otherwise require multiple setups.
• The Push and Lock arbor system eliminates the tool fumbling and thread-stripping frustration associated with traditional threaded hole saw connections, allowing fast, secure bit changes even in confined spaces.
• The variable 4-6 TPI pitch is engineered to cut both thin-walled tubing and thick plate in the same blade - reducing the need to switch between fine-tooth and coarse-tooth saws when material thickness varies across a job.

Specifications

• Manufacturer Part Number: 551-168X
• Brand: CMT Orange Tools
• Diameter: 6-5/8 in. (168mm)
• Cutting Depth: 45mm
• Blade Material: Bi-Metal (BIM) 8% Cobalt
• Tooth Pitch: Variable 4-6 TPI (alternate and side-set)
• Rotation: Right-Hand (RH)
• Shank: Hexagonal
• System: XTREME FAST Push and Lock
• Arbor Compatibility: 550-PH85 (11/32 in. hex) and 550-PH11 (7/16 in. hex) Push and Lock arbors
• Country of Origin: Made in Italy

Approved Applications

• Hole cutting in steel and stainless steel
• Hole cutting in cast iron
• Hole cutting in aluminum and non-ferrous metals
• Hole cutting in copper and brass
• Hole cutting in plastics
• Large-diameter conduit and pipe penetrations
• HVAC and electrical knockout applications