Cut Off Saw & Wheels

by Russ Rego
Makita 724504 12” Abrasive Cut Off Wheel 7/64” Thickness
Kalamazoo KM-14 Cut Off Saw
Pearl CW1420SR 14” Abrasive Cut Off Wheel 1/8” Thickness

Are you tired of cutting corrugated high-speed steel knife blanks for producing moulding knives that are severely burnt on the edges during the cut? Sometimes the burning can be so severe it takes the temper out of the profile area on the knife blank. Over the years we had the ability to use many different styles of chop saws and cut off blades for manufacturing moulding knives. We want to share some firsthand knowledge of what chop saws and cut off wheels we feel work best for our industry.

First, we recommend a cut off/chop saw capable of using either a twelve or fourteen-inch diameter cut off wheel with a one-inch arbor. Keep in mind that a twelve-inch wheel will result in less knife blanks cut per wheel, costing you more money over time for replacement blades. Something else you should consider is how much horsepower you will need on the motor. The higher horsepower motors develop cleaner, straighter cuts and generally have a longer service life. A decent chop saw could cost anywhere between $300.00 - $2,000.00, purchasing decisions will greatly depend on how much knife steel you think you will cut over time. We have cut thousands of high-speed steel blanks for manufacturing moulding knives over the years. We proudly own a Kalamazoo KM-14” (Made in the USA) five horse power chop saw with a Kalamazoo dust collection system (to keep our lungs clean). Most moulding production shops would not justify spending such a lofty amount just to cut knife steel blanks, but for us, cutting thousands of knife blanks over the years, the price is rationalized. For most small moulding companies any of the big box store brand of chop saws such as Makita, Milwaukee, DeWalt, or Porter Cable will work just fine for hundreds if not thousands of cuts.

Let’s briefly discuss which cut off wheel to use for the best overall success in cutting knife blanks, over the years we have tested about a dozen different abrasive cut off wheels. We had always returned to the Makita fourteen inch cut off wheel, part number 724603, the twelve inch part number is 724504. But over the last several years Makita has changed the thickness of these wheels to 7/64” (.109”) wide, thinner by 1/64” (.015”) This abrasive cut off wheel has always caused the least amount of burning on the side edges of the steel blanks while making the cuts. But that .015” smaller in thickness dimension causes the fourteen-inch cut off blade to wobble when cutting until it reaches about a twelve-inch diameter, then it works fine. We searched for a company that could make us a 1/8” thickness internally reinforced wheel that does not wobble when cutting in a fourteen inch version, after a long search we finally found Pearl Abrasives they have a premium cut off wheel that measures 14” X 1/8” X 1”, we now use and recommend this 1/8” thickness cut off wheel for cutting high speed steel moulding knife blanks.

There is a type cut off wheel we would advise to stay away from, the external reinforced wheels have viewable checkerboard fiberglass mesh that you can actually see; these types of wheels burn the steel too much on the edges, taking milling life away from your knife by reducing the temper of the steel. In our moulding knife designs we have 3/8” (Axial Constant) on each side edge of the profile so it is not a major issue. We know you will have better results with the internal reinforced cut off wheels like we recommend above, you won’t be able to see the fiberglass mesh reinforcement when looking at the wheels as seen in the images provided.

Most chop saws are available from your local home or industrial supply center, if you would like to purchase the cut off wheels we described above, please feel free to contact us we would be glad to help you.