Posted: Jan 27, 2012

Northern Tools ¾HP 8" Bench Grinder

Is this some kind of joke?

Available for $79 from Northern Tools (item #143388)

No tool is perfect. Even the best of the best won't be perfect at every task. And, generally, even the cheapest will generally do a servicable job at certain things. Occasionally, however, you might come across a tool that is so poorly built and performs its job so badly that it's not even worth $0. The Northern Tools 8" Bench Grinder is just such a tool.

I happened across this grinder and a Northern Tools grinder stand at a yard sale. The price for the set, still brand-new in sealed boxes, was only $10. Thankfully, the stand (which normally sells for $70) is quite nice, very well-made and sturdy. That way I can look at it as $10 for a great stand with a free boat anchor thrown in.

The grinder is a prime example of shoddy workmanship, poor fit/finish, inadequate engineering, and cheap materials. The instructions are poorly written (even by the low standards of most Chinese products) with multiple references to parts and features that simply don't exist on this machine. Several parts were bent or broken.

Two points bear special attention. The wheel covers on every other grinder I've ever used are held on with a bolt that goes into a tapped hole or a welded nut, that way you just need a screwdriver to remove it. On this grinder, it's just a plain nut, which means you need to juggle both a screwdriver and a wrench. The nuts sit right next to the lip of the inner shield, making them even more difficult to get hold of.

The second glaring failure: the shaft was slightly over 5/8", so any wheel or accessory with a properly sized hole won't fit. The wheels that came with the grinder had very rough holes, so they fit fine, but all my wire wheels and such wouldn't go over the shaft. Luckily, it wasn't over by much, so I was able to use some strips of 100 grit sandpaper held against the spinning shafts for a few minutes to remove enough metal to get them down to standard size.

Now, you may be inclined to still consider getting this grinder. After all, a little tweaking is to be expected with cheaper machines, right? Not in this case. Because when you turn it on, you're treated to an amazing amount of vibration, causing the stand to start turning in circles on the floor. And all that vibration starts the various thin metal parts like the wheel covers and guards to buzzing and rattling. It's really quite unnerving.

Now, before you start yelling foul and telling me about grinder wheel quality, I tried some other wheels. I put on a pair of wheels that came with my $200+ Jet grinder, it was just as bad. Thinking the grinder might be especially sensitive to an out-of-perfect-balance wheel, I pulled the wheels I use on my Jet grinder and tried them. These are high-quality Norton wheels that have been perfectly balanced using Oneway's balancing system. If anything, it was even worse!

In the final analysis, it seems the grinder runs nice and smooth as long as you don't put any grinding wheels on it. I tried out a wire brush wheel and the grinder runs fairly smooth with that, although it's pretty easy to stall it out with added pressure. Maybe those Chinese horses are a lot smaller. Anyhow, it works somewhat, so I'm going to bolt it down somewhere in my metalworking area and dedicate it to that. OK, maybe it's not totally worthless. But it's pretty darn close.