Tech Tip: Best practices for bi-metal hole saws

Bi-metal hole saws provide versatility to cut through many materials such as metal, plastic, copper, wood, fiberglass and aluminum. Unlike a drill bit, these hole saws make cutting faster and are designed to remove only a small percentage of material. 

Many technicians don’t recognize the usefulness or versatility of hole saws and choose not to use them. This is often due to previous difficulties and poor results they have encountered with their use.

Here are a few tips to avoid pilot bit breakage and damage to workpiece painted or finished surfaces.

To get the best performance out of bi-metal hole saws, Lawson Products recommends to:

• Avoid chip loading. When cutting into materials that are thicker than the depth of the saw teeth, chips will start to load up as the saw teeth become embedded in the workpiece. The loading will be followed by excessive heat build-up, vibration and chatter. Therefore, it’s important to stop and clear out the chips and not allow chip load to occur.
• Drill chip clearance holes through the workpiece. Make a light cut with the saw to scribe or mark the location of the hole. Then drill one or more holes through the workpiece on or adjacent to the cut. The holes will break up the chips and allow room for them to clear out and not pack within the cut.
• Properly set pilot drill. Whenever using a hole saw and a hand-held drill it is good practice to adjust the pilot drill extension according to the thickness of the workpiece. The pilot drill should be adjusted so that the saw teeth begin entering the workpiece just before the drill breaks through the back of the workpiece. This eases the transition from drilling to sawing and helps prevent saw teeth from abruptly crashing into the work.

Lawson offers Regency Bi-Metal Hole Saws which feature:

• Joined bi-metal construction enabling cutting of a variety of materials and extended saw life
• Slots for easy plug removal
• Variable tooth design for faster and smoother cutting with less vibration
• Thick, heavy duty backplate construction providing durability when used on hard metals

Information provided by Lawson Products.