The CMT 551-133X Bi-Metal Plus Hole Saw delivers professional-grade hole cutting performance in a 5-1/4 in. (133mm) diameter format, engineered for demanding applications in metal fabrication, plumbing, electrical, and HVAC work. Built with an 8% Cobalt bi-metal (BIM) construction, this hole saw provides twice the cutting life of standard bi-metal hole saws, making it a reliable choice for repeated use in steel, stainless steel, cast iron, aluminum, copper, brass, and plastics. The XTREME FAST Push and Lock system allows tool-free blade changes in under 3 seconds, dramatically reducing downtime on the job. Designed for right-hand rotation and compatible with hexagonal shank arbors, this CMT hole saw is a go-to solution for contractors and tradespeople who need consistent, clean holes across a wide range of materials.

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, reducing replacement frequency and cost on high-volume or tough-material cutting tasks.
• 5-1/4 in. (133mm) Cutting Diameter - a large-format diameter suited for cutting openings for conduit, pipe, HVAC fittings, and other trade applications that require precise, wide holes.
• 45mm Cutting Depth - provides enough depth capacity to cut through structural materials, thick-wall pipe, and layered panels in a single pass without repositioning.
• XTREME FAST Push and Lock System - enables tool-free hole saw changes in under 3 seconds, keeping work moving efficiently when switching between sizes or replacing worn saws on the job site.
• Variable 4-6 TPI Tooth Pitch with Alternate and Side-Set - the variable pitch reduces vibration and chatter, while the alternate and side-set geometry produces cleaner cuts and helps clear chips efficiently, preserving tooth life in hard metals.
• Right-Hand Rotation - matches the standard operation of corded drills, cordless drills, and drill presses, making this saw compatible with everyday drilling equipment without special setup.
• Hexagonal Shank Compatibility - works with Push and Lock arbors in both 11/32 in. hex (550-PH85) and 7/16 in. hex (550-PH11) configurations, providing flexibility across different tool setups.
• Broad Material Compatibility - cuts stainless steel, steel, cast iron, aluminum, copper, brass, and plastics, making this a single tool that handles multiple material types across trades.

Why This Product

• Built for tough metals that wear out standard hole saws fast - the 8% Cobalt BIM construction is specifically formulated to handle stainless steel and hardened steel, materials that quickly degrade lesser bi-metal saws. This means fewer saw replacements and more consistent performance across a full workday.
• The 5-1/4 in. diameter fills a common gap in trade work - this size is well matched to large-diameter pipe, HVAC duct penetrations, and electrical rough-in tasks where smaller saws simply cannot do the job. One saw handles a wide range of large-opening applications.
• Tool-free arbor changes eliminate fumbling in the field - the Push and Lock system removes the need for wrenches or adapters when swapping saw sizes, a practical advantage on job sites where time and hand space are limited.
• Works with the drill equipment you already own - the right-hand rotation design and hexagonal shank system are compatible with standard cordless drills, corded drills, and drill presses, so there is no need to purchase specialized equipment to put this saw to work.

Specifications

• Manufacturer Part Number: 551-133X
• Brand: CMT Orange Tools
• Diameter: 5-1/4 in. (133mm)
• 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
• Use with cordless drills, corded drills, and drill presses