Vibration is reduced by using a composite handle.
The handle has a ribbed texture that provides a firm grip.
Controlling feathering with a lever throttle is possible.
Conveniently small and lightweigh.
Air is directed away from the work surface by the rear exhaust air flow system.
Featuring a 1/4-inch 90-degree Angle Die Grinder and a 1/4-inch Medium Die Grinder, Astro Pneumatic’s 222 ONYX 2pc Die Grinder Kit is a great addition to any tool collection. The set includes composite handles that reduce vibration, a rib textured handle that provides a firm grip, and a lever throttle that allows for feathering control of the gun. These tools are small and lightweight, with a rear exhaust and built-in regulators as standard features.
Overall, the tools are well-made, but Astro messed up on a few minor details that should have been obvious.
Because these are inexpensive tools, my expectations are tempered by the knowledge that they are being used. One thing that strikes me as odd is that they got the expensive things correct while getting the inexpensive things wrong. The quality (despite the high price) is quite good. The most basic (and least expensive) details are not well thought out.
First and foremost, while the rubber molding around the body of the tools is pleasant to the touch, the molding is recessed for the operating levers, which is a major flaw. The molding on the angle grinder is surprisingly sharp, and when I squeeze the lever, the skin on my hands is consistently pinched and irritated. It’s a dreadful design, and the sharp edge is likely to be dangerous to anyone who has sensitive hands. It’s a hard rubber, but it’s actually sharp enough to cut through things like paper. Even though my hands are reasonably tough, getting pinched with the mechanical advantage of a long lever against a sharp edge is extremely painful. I was able to resolve this issue by trimming away the molding with a knife, which completely resolved the issue, but the tool now appears to be a hacked up used tool. The other [straight] die grinder has the same rubber molding design as the first, but the edges aren’t as sharp, and the larger diameter of the tool body appears to keep the tool from pinching the blades together. My suspicion is that it is particularly prone to pinching loose gloves, but I haven’t tried the tools with gloves on just yet.
The second issue I have with these is that they each use a different wrench size and shape. Seriously. To change dies on two different tools, four different wrenches are required. Of course, none of these wrenches are clearly labeled with the name of the tool to which they are intended to be attached. I have a large collection of inexpensive, unlabeled, stamped sheetmetal wrenches for a variety of air tools, almost none of which are the same size as the others. A standard collet size for dies has been established by air tool manufacturers, which is a welcome development.
Other Astro tools include air fittings, which is a nice addition to the overall package. These, however, do not.
I’d probably buy these again, but if I found myself using them on a regular basis, I’d probably upgrade to something better.
