Abrasive Selection: There’s the rub

To judge quality in abrasive products, you can (usually) rely on brand, price and your distributor’s expertise.

Your mother was right. You can’t judge a woman by her looks.

The same is true for abrasives you use on the job. You might be using a coated abrasive flap disc to clean metal surfaces and weld flash or wielding a demolition saw to remove structures damaged by a hurricane before rebuilding. When it comes to cutting, grinding, sanding and finishing metal or stone, abrasive products are essential. But you can’t always tell at a glance what’s a quality product and what isn’t.

“Appearance alone doesn’t reveal the quality and engineering behind abrasive products,” Chris Weiler, vice president of marketing for Weiler Corp., says. “For instance, with a coated abrasive flap disc, there’s some trial and error involved in finding the right product for the specific job at hand. Your application, abrasive grit and the backing material of the disc can affect results. Some abrasives just need to be used to judge their quality.”

That said, there is something to be said for brand name products.

“A lot of United States manufacturers have spent considerable time and energy in developing brand name awareness, preference and quality/brand name identification,” notes Mike Terrill, executive vice president and COO of Even Cut Abrasives. “The good companies would go to any length to maintain that quality image and brand name connection.” 

But if you can’t judge quality by looks, don’t have time to test different abrasive products and can’t be sure that your preferred brand is best for the application, what’s an industrial user to do? Abrasive manufacturers have three suggestions.

Ask the experts
First, study up on the subject. Several abrasive product manufacturers offer free training courses. These crash courses in abrasives science typically cover which abrasives are best for specific applications and offer tips on how to gauge the relative quality and durability of comparable products.

Distributors are another good source of information. “Today’s industrial supply houses stay on top of industry trends and new products,” Jim Ballou, marketing manager at PFERD, explains. “They have experience with product performance through their customers, and it’s in their best interest to supply industrial users with the right tool for the job.”

He adds, “With distributors’ knowledge, experience and factory training, they’re an excellent source of advice on choosing a quality product.”

All manufacturers agree that quality is important. Safety for users is the prime concern. They engineer their products to fit a tool, a power range, spindle speed or tool rpm. They also consider the material of the work piece.

“Abrasive engineers know soft aluminum is prone to loading problems while an exotic alloy with high nickel content is very hard and difficult to grind,” Ballou says. “They design a wheel or other abrasive product for an intended application, but it’s common for users unfamiliar with the great variety of consumable abrasives to employ that wheel for a whole host of unintended applications. Improperly used, an abrasive product will not perform well and waste your time and money. In the worst case scenario, injuries can occur.”

For example, some users think that all 14-inch wheels are alike. If such a user were to mount a chop saw blade onto a hand-portable saw, the results would be extremely dangerous.

Low-powered electric chop saws require wheels, which are free cutting, and don’t need much pressure to work their way though the cut. To accomplish this, there’s a single or double layer of fiberglass reinforcement in the chop saw wheel.

‘Fiberglass does not cut. It’s there for safety, but it inhibits cut rate,” Ballou explains. “So for low-powered stationary wheels, where there’s minimal lateral pressure, manufacturers minimize the amount of fiberglass to maximize cutting performance. Our portable wheels, for example, have internal and external layers of reinforcement that’s much stronger than what’s used in chop saw wheels.”

Simply put, mounting that same size wheel on a chop saw will at the very least stall the motor. If a user puts the wrong wheel on the wrong machine, the result is lost performance and safety. In a worst case scenario, it could cost a life.

Let price guide you
In general, you can assume that the more you pay for abrasive products the better the quality, the greater the value and the safer the wheel will be, according to our manufacturers.

A higher price tag reflects quality manufacturing equipment, good engineering and a manufacturer that invests in new products and customer training.

“There are multiple values in the decision matrix of purchasing any product, whether its abrasives or cutting tools or hand tools and price is just a minor component,” Terrill says. “Productivity, finish and labor savings in most cases far outweigh any advantage you may have in buying a less expensive, ergo, a lesser quality product. Performance and finish are more important than price.”

“Price and quality go hand in hand,” agrees Weiler. “Better quality products can give you longer life, so the cost per use is actually less, compared with lower-priced items.  You really need to consider how much work you want to accomplish before you put a new wheel on the power tool and the labor cost involved in frequent changeovers.”

He points out that paying a higher price may also give you flexibility:  “Some abrasive products, like a flap disc, allow you to do more than one job, such as grinding and finishing.”

Ballou points out that some users focus on low-priced products not because they don’t care about safety or product life.

“Waste is extremely difficult to control,” he says. “If an operator is cutting concrete with a portable saw and needs to switch to a steel blade, the partially used concrete blade is usually discarded. Only a new wheel will be mounted. When wheels are not used to maximize their service life, then it is impossible to benefit from quality.”

Realizing that users need abrasives for small and large jobs, manufacturers often offer tiers of products.

“Premium products last longer, so if you have a big task to accomplish and finish is important, a bargain won’t last. You want to pay for top-quality abrasive products in that case,” Weiler notes. “If it’s a small, limited application, a lower-cost product may do the job.”

Ballou concurs. “Manufacturers typically produce multiple performance tiers in some product lines. For example, in the .045 wheels, PFERD manufactures a general-purpose wheel (orange), a high-performance wheel (silver) and a premium performance wheel (blue).”

He explains that the cut rate of the three levels is pretty close, but the service life extends dramatically as you step in up performance levels.

“If you’re going to make three cuts and then throw the wheel away, a general-purpose wheel is the right choice from a financial perspective,” Ballou says. “However, if workers can be trained to fully consume the wheels, a higher quality line can offer the best value.

In other product lines, such as the portable wheels for demo saws, you may find only one quality level. “From our perspective as a manufacturer, users of these wheels need the safest, strongest, fastest cutting and the longest lasting wheels possible,” he notes.

Buy a recognized brand
The three manufacturers agree that you should rely on well-known brands and ones that you’ve had success with in the past.

If you test one brand of burr and like it, chances are you’ll test that same manufacturer’s grinding wheel. Ballou explains, “PFERD, like all manufacturers, recognizes that the success of our organization demands a consistent high quality across all of our product lines.”

He also advises: The contractor interested in determining which brand best suits his tasks should put the products to a side-by-side test. It doesn’t matter whose wheel has the prettiest label or a name you recognize from a car race. What matters is performance.”

More tips
The wide range of abrasive products and their potential applications could fill this magazine. Safety tips could as well, but our manufacturers offer a few additional tips:

• Look at the packaging to see if the manufacturer is affiliated with safety groups, like the Organization for the Safety of Abrasives (OSA).

• Buy the correct abrasive for the tool it will be used on and the task to be accomplished. Check the RPM of the abrasive product and the maximum RPM of the tool.

• Be careful not to put a cutting wheel designed for a chop saw on a gas-powered saw. Gas powered saws need wheels that are designed for greater lateral force. These wheels have additional reinforcement for safety.

• Never grind with a cut-off wheel.

• Cutting wheels designed for electric circular saws are a wonderful choice for the contractor when cutting large pieces of thin sheet steel. These abrasive cutting wheels work just like saw blades for wood. They cut straight and are safe to use.

• Try a segmented flap wheel or flap disc.

Proper abrasive care
There are two main care objectives when handling and storing abrasive products:

1. Keep them dry — Humidity can warp these products and will drastically affect performance, so keep them in a dry place, away from excessive heat and in their original packaging until use.

2. Handle with care — Dropping abrasive products may not shatter them, but cracks could occur that you can’t see. That will affect safe use. Also, don’t store cut-off wheels on their edges.

This article appeared in the December 2005/January 2006 issue of MRO Today magazine. Copyright 2005.

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