Cutting tool killers Clang them, toss them, bang them.  Those are three ways people damage reamers and drills.  Here's advice to protect your expensive cutting tools. by Paul V. Arnold Sometimes, it makes you think. Why does it take 10 minutes to make Minute Rice? Why don't they build airplanes out of the same stuff they use to make the black box? And why are tools that are made to bore into metal so easily damaged? The answer is misuse.  To the third question, that is.  The jury is still out on the other two. While a reamer, drill, end mill, tap or milling cutter can perform amazing feats with exceptional accuracy and speed, more often than not it is human action, and not tool composition, that leads to a breakdown. Breakdowns include chipping, dulling, burn-outs and blow-ups of the cutting tool itself and inaccurate holes in the items being bored. "A cutting tool is extremely durable, but improper use can damage or destroy it," says Steve Boyer, general manager of Alvord-Polk Tool Inc., Millersburg, Pa.   "It doesn't take much.  Even though you've got a hardened steel or carbide tool, a little misuse or mishandling can lead to chips or damage." Blame it on the bossanova Misuse can occur in a couple different ways. First, there is the blatant, "what the heck are you doing?" type of misuse. In every plant, you'll find at least one guy who uses his cutting tools as a musical instrument.  He puts two or three in his hand and clanks them together.  It makes a cool sound.  But even if he can make like Tito Puente on his carbide castanets, entertainment value comes at the cost of tool life. Cutting tools, especially those made of carbide, are prone to chipping when struck at the wrong angle by another hard object, be it metal or concrete. A reamer is designed and constructed to cut straight down into metal, plastic or wood, not take the brunt of a side or oddly angled impact.  The cutting edges are the most important and delicate part of the tool. Rap an edge just right and the next piece of metal it will find is the bottom of a garbage can. "We have people try to return them after they've chipped them," says Boyer.   "The first time, we replace the tool at no charge.  We typically write it off as a learning experience.  We do a little schooling to those people after that.   If it happens a second time, that's a different story." Toss 'em ... and toss away tool life Not as bad as "maraca man" but still in the same boat is the guy who tosses his cutting tools into a drawer, tray or bucket when he is done using them.  The result is the same, but you can't take requests like the clanker. Then there is the guy who tries to soup up his cutting tool as if it were a '57 Chevy.   He sands, shapes, gouges . . . and ruins. "We have found modifications in a lot of cases, where people have tried to adapt them to a job that the tool is not suited for," says Boyer.  "They say, 'I don't need to spend $20 for a special tool and wait six weeks for it when I can tinker with it and use it today.'  In their adaptation, they have modified the tool to where its properties or strengths have been diminished." The few dollars you save by modifying tools are lost when the tinkered tools break down.   That breakdown has the potential to shut down an assembly line. A little planning and ordering can have those special tools on hand when you need them. Think straight While stories of wreckless disregard are more colorful and laughable, more often than not damage occurs as the result of simple errors in judgment. "Tool abuse is not as prevalent as sometimes using the wrong tool for the wrong application," says Boyer.  "They are commonly using the wrong tool for the job." Like using a straight flute when a spiral flute is the recommended tool.  Or using a high-speed steel tool when the job calls for one made of cobalt. Using improper speeds and feeds also hurts. "Wrong feeds and speeds will blow them up or burn them out," says Buck Huot, president of Huot Manufacturing, a St. Paul, Minn., producer of cutting tool storage units.  "If you want to damage them, that's a good way to do it." Generally, when you operate a drill within recommended speed limits for a specific material, increases in speed result in a shorter drill life between grinds.   Decreases in speed result in longer drill life. On most jobs, start with a slower speed and build up to the maximum after trials indicate the job can be run faster. Be Mr. Clean Using a tool in a collet that has not been properly cleaned is another tool killer.   Dirt, shavings or oil can accumulate in the collet and produce an improper fit. When operators notice a bad fit, they often "fix" it.  A common remedy is to take a rubber mallet and tap the tool into place.  Bad thinking.  Doing so can take pieces off the cutting edges. Instead, tool makers suggest you take apart the assembly, wipe out any cutting fluid residue, blow out the holder and collet, wipe off the shank and put it back together.   The few minutes it takes to clean the parts will be returned to you in longer tool life. Besides tool damage (chipping, warping or dulling), a bad fit can cause tapered, crooked, torn or non-circular holes. "What does a blown hole cost you?" says Boyer.  "It's a hole that is going to have to be redrilled and resized.  That's a big expense." Check it out The United States Cutting Tool Institute, an organization representing more than two-thirds of the domestic cutting tool market, has developed a 12-point checklist to pinpoint inaccuracies and equipment that is in poor condition. By following them, you can be sure your cutting tool achieves maximum life, your machine has fewer problems and the holes you create are true. The 12 questions: 1) Is the spindle snug in the quill? 2) Is the quill snug in its ways? 3) Is the table square with the spindle? 4) Does the spindle, table or column resist deflection under load? 5) Is the starting hole properly located? 6) Is the work immobile while being drilled? 7) If an indexing fixture is used, does the indexing occur accurately? 8) Are the fixtures designed to compensate for burrs left by previous operations? 9) Does backlash in the spindle cause irregular drilling at either end of the cut? 10) Do fixtures and bushings provide room for cutting fluids? 11) Do fixtures provide room for disposal of chips? 12) Does the machine have enough power to drive the drill properly? Host of products guard against damage If you want to prevent damage to cutting tools when they aren't in the toolholder, put them away in a protective tube, web sleeve, case or cabinet. While it may be easier to drop a reamer, drill or end mill into a drawer, tray or bucket after it is used, the chance is great that chipping or dulling will occur after the tool hits the metal container or when it bumps into another cutting tool. "People are more cost-conscious these days, so they need to protect their investment," says Buck Huot, president of Huot Manufacturing, which produces a line of products to house and protect cutting tools.  "Cutting tools are a high inventory cost item, so you have to take very good care of them." The quickest and easiest solution is to always put the tool back into the plastic tube that it came in and put the cap back on.  Tool makers ship their products in the tubes for protection.  Keep that protection handy.  Don't toss it.  Many companies also make special tubes.  Some are square so they don't roll. Another good idea is to label the tool's product number and specs on the tubes.  That way you always can find the right tool. Another inexpensive solution is to purchase web sleeves.  The webbing, made of tough, flexible and stretchable polyethylene, easily slips onto the tool to protect the delicate cutting edges.  The product's elasticity assures a snug fit. For a few dollars, you can organize and protect your taps and drills in an index, a small, enclosable case which arranges the pieces by size.  Or if you want to organize and protect a large number and variety of cutting tools, you can invest in a steel storage cabinet.  The cabinets house a host of drawers, each containing labeled compartments to place individual cutting tools.  To avoid tool bumping, compartments are lined and separated by dividers.  Huot and other storage companies also design custom cabinets for customers and their specific needs. "With a cabinet, you can control your inventory better," says Huot.   "As an end-user, you can open a compartment and tell exactly if you put it in the right slot.  The quarter-inch drill slot is pre-identified and prelabeled.   And you can look in there and see how many of that item you have.  If you see you have just a couple left and you use a lot of them, you know it's time to order more." This article appeared in the April/May 1999 issue of MRO Today magazine.  Copyright, 1999. Back to top Back to Uptime archives