The CMT 551-105X Bi-Metal Plus Hole Saw delivers professional-grade hole cutting performance in a 4-1/8" (105mm) diameter format built for demanding metal fabrication, electrical, and plumbing work. Constructed from 8% Cobalt bi-metal (BIM) material, this hole saw is engineered to outlast standard bi-metal tools and cut cleanly through stainless steel, mild steel, cast iron, aluminum, copper, brass, and plastics. The XTREME FAST Push and Lock system lets users swap hole saws in seconds without any tools, making it a practical choice for professionals who move quickly between hole sizes on the job. Right-hand rotation and a hexagonal shank provide secure, chatter-free seating in compatible arbors, so every cut stays on target.

Key Features

• 8% Cobalt Bi-Metal Construction - the elevated cobalt content in the BIM teeth delivers 2x longer cutting life compared to standard hole saws, meaning fewer tool changes and lower cost per hole when cutting stainless steel, hardened steel, and other demanding metals.
• Variable 4-6 TPI Tooth Pitch - alternate and side-set teeth at variable pitch reduce vibration and heat buildup across a wide range of material thicknesses, producing cleaner edges and faster stock removal in both thin sheet metal and thicker workpieces.
• XTREME FAST Push and Lock System - hole saw changes take under 3 seconds with a simple push and no tools required, dramatically reducing downtime when switching between diameters on multi-hole layouts.
• 4-1/8" (105mm) Diameter - sized for large-diameter penetrations in electrical conduit work, HVAC rough-in, and plumbing installations where a precise, clean hole is required through metal panels or structural steel.
• 45mm Cutting Depth - accommodates wall thicknesses and material stacks that shallower hole saws cannot reach, reducing the need for multiple passes or specialty extensions.
• Hexagonal Shank - mates securely with Push and Lock arbors (550-PH85 for 11/32" hex and 550-PH11 for 7/16" hex), preventing slippage under high-torque cutting loads.
• Right-Hand Rotation - standard RH cutting direction ensures compatibility with corded drills, cordless drills, and drill presses without any spindle reversing.

Why This Product

• Professionals cutting through stainless steel or cast iron need a hole saw that holds its edge under heat and load - the 8% Cobalt bi-metal formula provides that durability in a 4-1/8" format that covers large-bore penetration work in a single pass.
• The XTREME FAST Push and Lock mounting system solves the common frustration of arbor-locked hole saws that require wrenches or set screws to change, allowing fast, confident swaps directly on the drill without stopping to hunt for tools.
• At 45mm cutting depth, this hole saw handles material stacks, wall assemblies, and thick-gauge steel that would require a dedicated deep-cut tool from competing product lines - making it a versatile single purchase for varied job conditions.
• Variable pitch teeth (4-6 TPI) mean this one hole saw transitions cleanly between thin aluminum sheet and heavier cast iron without swapping to a specialty tool, consolidating your tool kit for multi-material projects.

Specifications

• Manufacturer Part Number: 551-105X
• Brand: CMT Orange Tools
• Diameter: 4-1/8" (105mm)
• Cutting Depth: 45mm
• Blade Material: Bi-Metal (BIM) 8% Cobalt
• Tooth Pitch: Variable 4-6 TPI (alternate and side-set)
• Shank: Hexagonal
• Rotation: Right-Hand (RH)
• System: XTREME FAST Push and Lock
• Arbor Compatibility: 550-PH85 (11/32" hex) and 550-PH11 (7/16" hex) Push and Lock arbors

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