January 17, 2014
Small angle grinders are incredibly flexible tools; however, even they have their limitations, like accessing confined spaces. A power tool manufacturer with U.S. headquarters in West Chester, Pa., developed a small angle grinder with a reduced profile that reaches into tight spaces not normally accessible with standard angle grinders.
Not all angle grinders are created equal. Large angle grinders are meant for heavy-duty cutting and grinding work, while smaller versions of the tool are better suited for light grinding, deburring, finishing, and polishing.
It is for that reason Terry Tuerk, senior product manager at Metabo Corp., West Chester, Pa., considers the small angle grinder to be one of the most versatile tools available. That versatility can be dangerous, however, especially when clever metal fabricators try to alter these tools to fit their own individual needs.
One example of this, Tuerk recalled, was when a Metabo sales representative met a customer who had altered his small angle grinder to reach an area that that tool couldn’t otherwise. The customer had welded a 9-in. guard to the 5-in. guard, put it back on the tool, and then attached a 9-in. cutting wheel.
“This was a piping application, and I believe it was a 36-in.-dia. pipe with 6-in. wall thickness. It was heavy pipe that needed to be welded. They went in and did a root pass on the weld and then they’d have to go in through the bevels of the pipe and grind the root. They couldn’t get there with an angle grinder, so they developed their own,” Tuerk explained.
That’s when conversation began within the company about developing an angle grinder with a flat or reduced profile that would give end users the ability to access tight or confined spaces more safely and more easily. After all, if one person altered this angle grinder, how many others had done the same thing?
“We’re very close to our end users. We collect feedback regularly from them through our salespeople. We want to find out what the market need is, what the issues are, where we can improve, and what we should be doing differently. This was just one of the ideas that came out of that feedback—the flat-head grinder. And that was one of the specific applications—the grinding of a root weld in a deep piping application.”
Other industries where the company found a need was shipbuilding, steel fabrication, and boilermaking.
“There are always areas that you just can’t reach with an angle grinder. You need to get into a fillet weld, so typically people will use a die grinder with a carbide burr to get in and grind out the weld. Or sometimes people will use a needle scaler to get in and break the slag off of a weld. Needle scalers traditionally are loud, they vibrate a lot, and they can be pretty uncomfortable to use. Die grinders are better, but still with the positions you need to get into you can put a lot of pressure on the burr, which tends to bend and break sometimes,” Tuerk said.
The flat-head angle grinder officially launched in Europe last fall, and to the company’s surprise, demand for the tool was 12 times higher than projected, which threw the company for a loop.
“We fabricate all of our own die-cast aluminum housings, injection molding, and turnings. We’re a manufacturing company, not an assembly company, so everything from the ground up had to be reworked.”
Tuerk expects the grinder to become commercially available in the U.S. in early 2014. The tool accommodates 4-, 4½-, and 5-in. wheels and has a patented gear drive that has reduced the tool’s profile, allowing it to access acute angles as small as 43 degrees and into spaces as narrow as 25⁄8 in. Standard angle grinders typically access acute angles of between 68 and 70 degrees.
The tool comes standard with an electronic safety clutch that shuts down the machine automatically should the grinding or cutting disk jam. An overload sensor shuts down the motor if the operator is pushing down too hard, and each user can position the switch in one of four configurations—top, bottom, left, or right.
The first versions released in the U.S. will feature a side lock-on switch. A nonlocking paddle switch version will be released by midyear. The tool will be available in both corded and in an 18-V, cordless model that has a 5.2 amp-hour battery. Tuerk said the cordless version will also be available as a paddle-switch version by midyear.
Even though the tool isn’t available in the U.S. yet, Tuerk expects it to be received with the same enthusiasm as it was in Europe. And based on the reception the prototype version has gotten, he might be right.
“I was at a shipyard with the machine—they do military work like nuclear submarines, and they’ve got two aircraft carriers they’re working on. We showed the flat-head angle grinder to the tool guru of the shipyard, and he looked at it knowing the application they needed it for and said, ‘How quickly can I get 10,000?’ Just showing him the prototype of the tool … they knew the application and had a demand for them right away.”
Practical Welding Today® was created to fill a void in the industry for hands-on information, real-world applications, and down-to-earth advice for welders. No other welding magazine fills the need for this kind of practical information. Subscriptions are free to qualified welding professionals in North America.