Trick-Tools Hole Saw Notching Tips - Pictured is one of our many hole saw style notchers in stock at Trick-Tools.com.
So, youíre 20 notches into your latest tubing project and the 3rd hole saw in a row binds up. It twists your arms like a pretzel and distorts the cutter to the point you can measure its run out with a yard stick. Hole saw notching is for the birds, right? They never work! Well, there are a few hole saw notching tips we can look at to help you extend the life of those inexpensive cutters. Follow these tips to help save your wallet and your wrists from drill-induced torture.
Hole Saw Notching 101
First, letís check out the brains of this operation Ė yes, you the operator! Iíve lost more hole saws than I care to admit. Usually by getting in a hurry or not paying close enough attention to what Iím doing. The number one killer of hole saws in my shop has been not removing the little slug that breaks off on the first half of the notch. When you pass through the first side of the tube, a little hole saw-slaying slug will break off, often inside the cutter itself. STOP! Back up the hole saw and take that piece out before continuing. If you donít, often, it will poke its devilish little head out of a vent hole in the side of the cutter and wedge itself against the tube. Game over for the saw and the use of your right hand for a while.
Trick-Tools Hole Saw Notching Tips - Note the slug in the hole saw vent after the first half of the notch.
Drill Choice and Cutting Speed
You donít need anything special to extend the life of your hole saw. A quality 1/2-inch corded drill does the job well, preferably a drill with slower RPM speed and good torque. Personally, I use a Milwaukee 0300-20 drill with a max speed of 850 RPM. I wouldn't want anything slower, but not much faster either. Iíve tried to run the drill at half speed or less and the cutter tends to catch and bind more often. This can cause it to chip off teeth or bind up the hole saw in the material. Start relatively slow, and ease the cutter into the tube. When the teeth are engaged into the material, speed up the drill and let the cutter do the work.
Trick-Tools Hole Saw Notching Tips - The tube should be cut and positioned at about 50% of the hole saw diameter.
Proper Notch Depth
Cut depth is next on our checklist to notching nirvana. Donít plunge the hole saw into the tube 6 inches from the end. Do not use the notcher to cut your tube to length! Iíve done it, itís dumb, and youíll wear out a hole saw faster than you can imagine. A good notch depth will just barely leave the long edges of the ďfish mouthĒ shape untouched by the hole saw. Any deeper and youíre engaging too many teeth into the material.
Trick-Tools Hole Saw Notching Tips - Stop! Get that half slug out of the hole saw!
This can build up too much heat in the hole saw and wear out the cutter faster than normal. That little slug we talked about earlier will break off inside the hole saw when notching to the proper depth. Donít forget to stop and get him out! Beware as you pass through the first half of the tube to continue cutting. Make sure that you start the drill and ease your way back into the notch. Do not to ram the hole saw into the opposite wall, this will surely catch and bend your hole saw ending its life prematurely.
Trick-Tools Hole Saw Notching Tips - A completed notch resembling a "fish mouth".
What to Look for in a Hole Saw
If you take heed of the hole saw notching tips noted above, you should be making some good notches and getting your moneyís worth out of these $12-$15 hardware store heroes. The last items to look at are the hole saw itself and the cutting lubricant. No matter what, occasionally, the cutter is going to bind up, the drill will stall, or something else will happen that puts a huge load on these thin steel constructed cutters. Some hole saws are constructed with a thin stamped sheet metal base. This thin base can distort and ruin a hole saw long before the teeth ever wear out or break off. I prefer to use hole saws that have a thick steel base plate. This more rigid design seems to be less prone to binding, and when the cutter does bind up, less likely to destroy the hole saw.
Trick-Tools Hole Saw Notching Tips - note the differences in the mounting bases of the 2 hole saws with the right saw having a thicker base material.
The Final Word on Notching Bliss
A good quality cutting lubricant can also help to reduce heat in the cutter and extend blade life. WD40 and similar products are probably not the best choice for this, as they are primarily solvents, and youíll have to use some type of weld-safe cleaner to remove the residue left behind. I prefer water based cutting lube that can be simply wiped off with a rag when finished.
Trick-Tools Hole Saw Notching Tips - Trick-Tools Notching and Cutting Lube.
While the number of notches per hole saw can vary based on a lot of factors. With a little bit of practice using these hole saw notching tips, you should expect to get 50+ notches in mild steel and around 20-30 in chromoly. Get yourself in-tune with your notcher, the drill, hole saws, and the proper notching procedures. When you do, you wonít cringe when it comes time to take on that next tubing project.
For more information on available products or for help on deciding the best application for you, contact Trick-Tools at 877.826.7286
Written by: Christian Huffman