DA31325GF 100 Grit Coarse Diamond Grinding Wheel Replacement

While the replacement wheel for a Drill Doctor sharpener looks great, it is not the correct one for a model shown. My Drill Doctor 750X has a different wheel that is larger. I could see the difference without taking my machine apart. I thought that I had made a mistake when ordering so I checked the model and the listing again but it’s the listing that is wrong.

Works great in my 500X, installation was easy, finish looks good on the bits after grinding, works just like the stock original one. The two included screws were not needed on my 500X, not sure if this is a Drill Doctor change on later models or if its for earlier models and i have a later model, but my 500X has a single screw in the center of the grinding wheel, not two screws that hold the wheel on, so i didn't need the two included screws, but looking at their product pictures they show a unit with two screws holding the grinding wheel in place so there must be some out there that are like that. Seems to be the same material as the original, leaves a nice finish on the bits, good value for the money. The original OEM wheel is also 100 grit, and only a few dollars more for a replacement, so the real test will be how it holds up over time, my original wheel sharpened hundreds of bits and was only just starting to get worn to the point it wouldn't quickly grind away the bit edges anymore. Edit: Looking at the other reviews, others had issue with the interior diameter of the wheel, this wasn't a problem on my 500X because of the single screw tapered retainer/collet it just centers it as the screw is tightened, so they must have a different version?

This 100-grit diamond replacement wheel is an unfortunate example of an aftermarket part that fails on basic technical specifications. While the quality of the diamond coating itself is good, the wheel is ultimately useless as a direct replacement for the Drill Doctor. Critical Technical Failure: The interior diameter of this diamond sleeve measures 14.57 mm (~0.575 inches), which is significantly larger than the standard 0.5-inch arbor found on Drill Doctor machines. Because of this oversized gap, you cannot mount the wheel in a centric way. Without a specially purchased or custom-made bushing to compensate for the extra space, the wheel will wobble violently, making it impossible to sharpen bits accurately or safely. Conclusion: It is unfortunate that the manufacturer didn't match the interior diameter to the machine it is advertised for. Unless you have the means to shim or bush the arbor to account for the loose fit, do not buy this as a replacement. The quality of the grit does not matter if the wheel cannot be properly mounted.

I wanted to like this wheel but there are some issues. The grit seems fine, but as you can see from the pictures it is unevenly applied on the ends. That’s not really the issue and not why I rated this 1 star. The bore of the diamond wheel will not fit the Drill Doctor 750X and since most of the Drill Doctors use the same wheel it won’t fit the others either. It is 0.1 mm too small (I measured it with calipers multiple times). I debated trying to hand ream it out but the issue is that if the bore isn’t exactly concentric you will get high speed wobble and that won’t work very well when trying to sharpen a drill bit. For this reason this wheel is completely non functioning for the use it’s advertised for.

Unfortunately I was unable to properly use the grinding wheel. The inside bore diameter is too small. The grit construction looks to be good but the overall build quality is subpar compared to the original. Grit is stuck to the sides and the machine quality is poor. It's very easy to distinguish the difference between the factory and replacement.