Above: Starrett’s Primalloy blade cutting through stainless steel.
Affordability and quality are integral components of a successful saw shop
August 2013 - Sometimes the most expensive thing a saw shop can do is try to save cash by buying a less expensive blade without recognizing the benefits of one design over another.
“The bottom line is: Less blade changes and less down time equals more money,” says Dale Edmonds, sawing operator at K & D Cutting, Arlington, Wash. The majority of Edmonds’ customers are local machine shops serving the automotive, heavy equipment, aerospace and medical industries. “Pretty much any industry can walk through my doors,” he says, adding K & D Cutting handles jobs for other customers including Boeing, Genie and Ingersoll Rand.
The variety of jobs and materials Edmonds cuts requires a blade that can switch easily from one job to another without having to uninstall and reinstall different blades throughout the day. K & D Cutting processes numerous grades of steel, stainless steel, brass, bronze and aluminum alloys, among other materials. To meet the needs of his clientele, Edmonds cuts with saw blades from L.S. Starrett Co., Athol, Mass. He primarily uses Starrett’s Primalloy blades, which are made to cut low-alloy steels, aluminum, stainless steel, tool die and mold sheets, carbon steel, steels up to 45 HRc, nickel-based alloys, and nonferrous metals.
“It’s tough enough to handle the exotic metals as well as stainless steel and other tough-cutting materials and it’ll cut mild steels just fine,” Edmonds says. “It’s a very versatile blade.” Edmonds uses Starrett’s M51 for mild steels but likes that if he needs to cut only a few pieces, he can leave the Primalloy blade in without having to make a change for a quick job.
Using the right blade
Edmonds found Starrett’s M51 blades cut fast with a good finish. “Most of my work goes out 1⁄8-inch over finish so machines have something to trim off,” explains Edmonds. “I have some situations where I had ±0.005-inch on a band saw. Trust me, that’s something customers had a hard time believing, but it worked.”
He also uses Starrett’s Intense Pro VTH blades, considered the workhorse of Starrett blades. “The Intense Pro VTH blade looks funny when it’s running because it goes in a sine wave,” says Doug Fordham, cutting specialist at L.S. Starrett. However, it cuts clean and removes chips and takes another group of chips so it doesn’t work harden. “Anytime you start rubbing titanium, Inconel or stainless steel, it’s going to start work hardening on you, so it’s important to take a nice chip every time.”
With the wide variety of saw blades available in the marketplace, it’s important to pursue technological innovations where possible. “You have got to be at the top of your game all the time by trying to innovate. Everyone always says they have something new that works better,” Fordham says. Starrett’s Primalloy blade is an example of that research at work. Made of cobalt, it contains three times the amount of vanadium, making it more wear-resistant. It also is 10 percent cobalt, making it harder and allowing it to be more forgiving than its more expensive counterpart, the carbide blade.
“If you get a hiccup while cutting and bust some teeth out of a carbide blade and need to replace it, that’s a very expensive hiccup,” Fordham says. “The Primalloy’s edge comes in between the M42 blade and carbide so it’s much more forgiving. You’re not going to shatter teeth on it. You get a lot more wear and a lot more bang for your buck.”
In general, there are three types of band saws. Scissors-type saws, which are the majority of saws out there, says Fordham, work off a pivot and come down on the material. Guillotine saws have two posts that come down on the material. A tilt frame saw stands up and an operator clamps the material, which then comes forward. As it moves forward, the blade cuts the material. The tilt frame can bridge between 45 and 60 degree angles on either side. “Each type of blade has its place in the sawing world,” Fordham says.
Having a lighter head on the saw while cutting with carbide can be difficult because it is too light. It wants to balance and the cut it’s trying to do is too heavy, so when the blade goes to grab the material, some teeth break off. This does not happen with a Primalloy blade because it handles varying thicknesses.
Starrett works with customers to find the best flow for a customer’s needs. By running the blade a little faster, the teeth are cleared quicker. When the gullet is filled with the chip, an operator ends up cutting sideways with it. When material is cut faster, those gullets are cleared faster as well, resulting in a faster cut. “Dale was cutting 2-inch and 3⁄8-inch stainless and 304L stainless, and he was able to get 2,500 pieces out of that,” Fordham says. “He was able to get those pieces at a very fast rate so he could get good use of shop time instead of having to go slower with an M42 blade. He’d have had to use three blades with the M42 or carbide had something happened—whether material didn’t clamp right or if he ended up ruining the blade, that’s a good amount of money compared to a Primalloy blade.
Starrett cutting specialists around the country coordinate with its research and development shop in Massachusetts. “When cutting specialists see a problem, we can talk to our R&D department and find a different tooth composition or a better angle to cut material,” Fordham says. “Sometimes we need to alter angles on a tooth or hook.”
Any test blade is taken out and tested for multiple jobs. Everything is recorded and reported back to R&D, including the type of metal and shape of material, square inches, whether cutting multiples or singles of that material, the speed force and band speed. “We take all that down and that goes back to Starrett so other sawing specialists can use that information too,” Fordham says. “We talk to each other and help one another out.”
Starrett sells blades but also prides itself on its follow-up service. “We don’t just show up, do the dog and pony show and then check out,” Fordham says. “We check the band tension, band wheels and stand there and find the dial-in to figure out the sweet spot for that customer’s needs.” The collaboration between Starrett and its customers includes blade suggestions. “And if our suggestion doesn’t work, we switch out to a blade that works without charging. Why charge the customer if it’s not the right fit?”
“I cut over a million parts a year; it’s a phenomenal business,” Edmonds says. “I don’t have the expensive major tool room filled with every drill or tool, I have boxes of blades.
“One of the big problems of being a specialty shop like this is anyone can buy a saw and put it in their shop,” he continues. “However the difference is whether they can have low enough prices while providing the expected finishes and tolerances—I’ve been doing this for 30 years, and most of my customers trust me enough to drop ship their materials straight to my shop. I unload the truck, check material in and I cut the order they send in.” MM