Hole Saws

The difference comes down to the hardness of the cutting tooth material and the maximum thickness of your target substrate:

• Bi-Metal Hole Saws: Use high-speed steel teeth welded to a flexible backing. They are highly flexible and impact-resistant, making them the premier choice for wood, plastics, and thin sheet metal under 1/8-inch thickness.
• Carbide-Tipped Cutters: Feature individual teeth forged from an ultra-hard tungsten carbide compound. They stay sharp up to 10 times longer when cutting dense structural steel, stainless plates, cast iron, and thick fiberglass composites.

A variable pitch design alters the size, throat depth, and setting angle of consecutive cutting teeth (such as a 4/6 TPI layout) instead of using one repeating uniform pattern. This shifting footprint completely breaks up mechanical harmonics during high-speed rotation, which eliminates harsh tool chatter and high-pitched screaming vibrations. It results in a much smoother cutting pass, drops your drilling hand fatigue significantly, and prevents the tool from kicking back violently if a tooth grabs.

The arbor (or mandrel) is the heavy-duty steel adapter block that locks the hole saw cup onto your drill chuck and positions the pilot bit. Selecting your arbor style depends entirely on the diameter of your hole saw:

• Small Arbors (1/2" Threads): Standard for small-diameter hole saws ranging from 9/16-inch up to 1-3/16 inches.
• Large Arbors (5/8" Threads): Feature heavy dual locking pins to support large-bore cups from 1-1/4 inches up to 6 inches, preventing the intense twisting torque from over-tightening or freezing the cup threads.

Industrial diamond hole saws do not feature traditional sharp metal teeth; they use exposed diamond crystal segments to physically grind through brittle materials like porcelain tile, glass, granite, and masonry. This intense grinding action generates extreme friction heat instantly. Running the tool dry will melt the diamond bonding matrix, stripping the cutting edge and ruining the bit in seconds. Applying a steady stream of cooling water clears out abrasive sludge and preserves your tool life.

Spent material cores expanding inside the cup layout is a common jobsite hassle. To address this, premium hole saws feature wide, offset ejection slots or stair-step windows cut straight into the steel side walls. To extract a stuck slug safely, pull your tool out of the drill spindle, slide a flat-head screwdriver or a thick alignment pin directly into the side window slots, and lever the plug forward past the front teeth rim without damaging the cup tolerance.

When boring through hard metals, you must drop your drill's rotational speed down significantly and apply constant downward pressure. Running a large hole saw at maximum RPM will instantly work-harden the stainless steel surface and roll your cutting teeth over, ruining the tool. For example, a 2-inch bi-metal saw cutting structural steel should run at roughly 170 RPM, whereas that same tool can safely spin at over 900 RPM when clearing soft pine lumber packages.

Hole cutting tracks throw off fine drywall dust, sticky wood pitch, and hot metal slivers that can easily slip inside the spring-loaded sleeves of a quick-change mandrel. Over time, this debris turns into a gritty paste that jams the sliding pins. To protect your investment, blow out the arbor tracking springs with clean compressed air after heavy cutting loops, clear away sap buildup with a wire brush, and add a light drop of machine lubricant to keep the pin collar sliding effortlessly.

As an authorized stocking trade distributor and commercial tooling supplier, Ohio Power Tool stocks a comprehensive portfolio of accessories. We maintain deep regional field stock on multi-piece master plumbing and electrician layout kits, carbide-tipped sheet metal cutters, heavy-duty hex arbors, deep-cut wood saws, and extension shanks to ensure your active contracting, fabrication, and building maintenance crews maintain maximum continuous production.