The CMT 551-102X Bi-Metal Plus Hole Saw delivers professional-grade hole cutting performance in a 4" (102mm) diameter format built for demanding metalworking and fabrication applications. Engineered with an 8% Cobalt bi-metal construction, this hole saw provides twice the cutting life of standard bi-metal hole saws, making it a reliable choice for cutting stainless steel, carbon steel, cast iron, aluminum, copper, brass, and plastics. The XTREME FAST Push and Lock system allows tool-free blade changes in under 3 seconds, keeping workflows moving without interruption. Designed for use with cordless drills, corded drills, and drill presses, the 551-102X is a versatile metal-cutting hole saw suited for HVAC installers, electricians, plumbers, and metalworkers who need consistent, clean results across a wide range of materials.

Key Features

• 8% Cobalt Bi-Metal (BIM) Construction - the elevated cobalt content in the tooth material delivers 2x longer cutting life compared to standard hole saws, reducing replacement frequency and downtime on the job.
• 4" (102mm) Cutting Diameter - sized for large-diameter holes required in conduit runs, pipe penetrations, HVAC ductwork, and structural metalwork, eliminating the need for multiple passes or secondary finishing.
• 45mm Cutting Depth - sufficient depth to cut through thick steel panels, structural members, and stacked materials in a single operation, improving efficiency on heavy fabrication work.
• XTREME FAST Push and Lock System - compatible with the 550-PH85 (11/32" hex) and 550-PH11 (7/16" hex) Push and Lock arbors, enabling tool-free hole saw swaps in under 3 seconds so you can move between sizes without hunting for a wrench.
• Variable Pitch Teeth - 4-6 TPI with Alternate and Side-Set - the variable tooth geometry reduces vibration, prevents tooth stripping, and produces smoother cuts across both thin sheet metal and thicker stock.
• Right-Hand Rotation - matched to standard drill driver rotation so the saw engages material correctly without any reversal or adapter needed.
• Hexagonal Shank - the hex shank design locks securely in the arbor to prevent slipping under high-torque cutting loads, maintaining accurate hole positioning throughout the cut.
• Compatible with Stainless Steel and Hardened Metals - the 8% Cobalt bi-metal formula handles hardened and abrasion-resistant materials that defeat standard high-speed steel hole saws, expanding the range of applications this single tool can address.

Why This Product

• When cutting frequency is high and downtime is costly, the XTREME FAST Push and Lock system removes tool-change delays entirely - swapping to a new diameter takes under 3 seconds, which adds up to significant time savings across a full workday.
• Stainless steel and cast iron are notoriously hard on cutting tools, but the 8% Cobalt bi-metal teeth are specifically formulated to outlast standard bi-metal hole saws in these demanding materials, making this a cost-effective choice for shops and crews that cut these metals regularly.
• At 4" (102mm) with a 45mm cutting depth, this hole saw handles large-diameter penetrations through substantial material thicknesses in one pass - ideal for electrical conduit, plumbing rough-in, and mechanical system installations where a clean, correctly sized hole is critical.
• The variable 4-6 TPI tooth pitch with alternate and side-set geometry reduces chatter and blade wear across both thin-gauge sheet metal and heavier plate, so one hole saw performs reliably across multiple material types without needing to swap to a specialty blade.

Specifications

• Manufacturer Part Number: 551-102X
• Brand: CMT Orange Tools
• Diameter: 4" (102mm)
• 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" hex) and 550-PH11 (7/16" 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