If you own a set of drill bits or screw bits, if you have awls or chisels, sooner or later you’ll need to sharpen them. That’s where Bench Grinders come in. Your better half’s kitchen knives? You bet!
However, Bench Grinders are good for much more. They have two grinding wheels which have different grades and grits. Each wheel is used for a different set of purposes and applications. The wheels are typically designated ‘coarse,’ ‘medium,’ or ‘fine,’ and these labels indicate grits of, respectively, 16 to 24, 36 to 60, and 80 to 120.
In general, the coarser the wheel the better it is for shaping metals, forming metals and correcting form, and for bulk grinding and material removal. The finer the wheel, the more useful it is for fine sharpening, correcting or re-forming soft metals, and also for finishing and even polishing.
Bench grinders – heavy-duty ones – are mainstays in tool shops, metalworking shops, and fabrication shops where they are used on a daily basis. These are usually of cast-metal construction, have variable speeds, and sport powerful motors of 370-plus watts. The medium-duty and light-duty ones reviewed here have a single speed and have motors of 150 to 370 watts. They are suitable for non-trade use by DIYers, from enthusiasts who enjoy metalworking to gardeners who want to sharpen and re-shape their implements.
Professional use or hobbyist use, almost all bench grinders have a few safety features like eye shields and wheel guards but their sizes, adjustability, and quality vary.
A bench grinder’s wheels can be replaced and one must do so when a wheel is damaged or worn out beyond correction through dressing. However, it does not make sense to buy a bench grinder with inferior wheels and replace them because it is the wheels that make the bench grinder.
Though one wouldn’t expect it, bench grinders can be very dangerous power tools if they are misused. Significantly exceeding a grinding wheel’s maximum RPM rating can cause it to shatter or even explode, inflicting serious injury upon the operator. One risks similar ill effects if an unmaintained and undressed wheel overheats or if the edge or side of a wheel is misused for grinding. The possibility of wheel explosions is the reason behind wheel guards and eye shields without which a bench grinder should never be used.
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A wheel diameter of 150 millimetres is the most common one for enthusiasts and semi-pro twin-wheel bench grinders, and all five selections below have 150-millimetre wheels.
With nary an operational flaw, Sealey’s grinder has so much going for it from good power and smart design to standout features that any DIYer will be happy.
Sealey’s medium-duty bench grinder is fitted with coarse and fine aluminous oxide wheels. They are driven at a speed of 2,850 RPM no-load by the 250-watt induction motor.
The wheels are exceptionally well balanced and vibrations are next to non-existent. The machine also runs quite quietly and also reliably.
It has big, solid wheel guards and good-sized perspex eye shields. Admirably sturdy tool rests that are adjustable back-and-forth round out the ‘usual’ features. The standout design feature is the built-in wheel dresser to keep the wheel clean and true.
The work light mounted on a flexible and adjustable column is another thoughtful feature.
Assembly may be a perplexing chore for the beginner as no assembly instructions whatsoever are provided. It’s a bad miss and an unnecessary omission on Sealey’s part.
This solid and robust bench grinder manifests very good build quality. The 250-watt motor has sufficient grunt for just about any DIY task. It is a clear top choice for hobbyists’ workshops.
This grinder even comes with a water tray for cooling tools. (Metal heats up a lot while it is being ground due to friction.)
The BG150WL measures 27.8 x 42.6 x 27.6 centimetres.
Sealey provides a one-year guarantee.
- Nearly vibration-free and quiet operation.
- This very solid and robust tool has excellent construction.
- Convenience features like built-in dresser and handy cooling tray.
- No assembly instructions.
- Assembly may be troublesome for unseasoned DIYers.
Though Silverline’s grinder is not perfect, its shortcomings are balanced out by its solidity and dependability and, above all, by its remarkably low price.
Equipped with a medium and a fine grinding wheel, Silverline’s budget-priced kit has 150 watts of power.
The steel wheel guards are solid and inspire confidence but the eye shields could have been bigger and clearer. The steel tool rests do not feel very firm or secure but are adequate. They are adjustable along the front-and-back plane.
The feet are capped with rubber pads which significantly damp down vibrations. Moreover, the 263511 runs without much noise at all. However, after about 20 minutes this grinder starts getting hot.
Now and then a wheel on a unit is not correctly balanced. Quite a few units have non-standard plugs.
If you go heavy on this kit the wheel will slow down as it is low in torque and power, but then this is a low-powered, light-duty kit meant for occasional use in the home and marketed to DIY enthusiasts. Use it for sharpening tools and bits, but shaping and forming metals is beyond its capacities.
Silverline’s 150-watter is so cheap that even if it were a so-so bit of kit it would be decent value for money but it is rather better than so-so; solid and dependable, at the price it is a terrific value for money.
It measures 29.5 x 20 x 21 centimetres.
Silverline provides a three-year guarantee upon online registration of purchase.
- Low vibrations and even lower noise.
- Reasonably solid and dependable kit.
- You can buy it using pocket change – top value for money.
- Low-powered motor means this grinder is good for only light-duty use.
- Some units have non-standard plugs.
- Eye shields’ quality and size are not up to par.
Einhell’s mixed bag has a low-power motor but excellent wheels, and while it has obvious vibrations, assembly is easy, the kit is sturdy, and the price is low.
Einhell’s grinder has a ‘coarse’ and ‘fine’ grinding wheel but with grits of 36 and 60 they are more like coarse-medium and fine-medium wheels. The 150-watt motor rotates the wheels at 2,950 RPMs no-load.
It has rubber pads to reduce vibration transfer but these very rubber pads and the vibrations themselves cause this kit to slip-slide around so you’ll really have to bolt it down or secure it with clamps. However, operation is very quiet.
The wheel guards are thick and solid.
The tool rests are adjustable along the front-rear plane by loosening a pair of screws and shifting the bracket. The round eye shields are good-sized and they are adjustable too.
With a 150-watt motor, this is a light-duty grinder so you cannot put much pressure on a wheel as it will cause the rotation to slow down and the motor to struggle.
Sometimes a grinder gets packaged and sent without bolts, rests, or some or another small part.
Notwithstanding the low-powered motor, both grinding wheels are excellent. The fine-medium wheel is good for sharpening all manner of tools, from gardening implements to carpentry chisels and the other one is useful for shaping soft metals and for light material removal, albeit slowly.
All components are of decent quality and the kit is reasonably sturdy and impressively so at the price.
Assembly, comprising of fitting the eye shields, guards, and rests, is not difficult.
Einhell’s TH-BG is a very good value for money and it is a sensible choice for DIY enthusiasts on a budget.
It measures 29.5 x 20.5 x 20.5 centimetres.
Einhell provides a two-year guarantee provided the machine is not used professionally or in the trades.
- Very good grinding wheels, especially in a budget kit.
- Quite solid and sturdy.
- Very inexpensive, it is an excellent value for money.
- Low-powered motor means this grinder is good for only light-duty use.
- The vibrations make this bench grinder ‘wander’ so it must be bolted or clamped.
- Some units turn up with one or another small component missing.
Brawn, ruggedness, and robustness distinguish Lumberjack’s grinder, yet it is so refined – it has virtually no vibrations and its eye shields are matchless.
Lumberjack’s bench grinder has coarse-medium and fine-medium wheels of grits 36 and 60. However, this one has a relatively brawny 250-watt motor that turns the wheels at a no-load speed of 2,850 RPM.
The tool rests are adjustable front-and-rear but it is a pity that they are not wider and deeper, especially in view of the grinder’s overall quality and the motor’s power.
The eye shields are from the top drawer; they are adjustable, large, and magnifying.
The heavy-gauge steel base is meant to enhance stability and reduce vibrations, and so it does! This grinder has virtually no vibrations; it stays put and doesn’t ‘wander.’
The LED light is adequate.
This kit’s low noise is surprising considering the relatively strong 250-watt motor.
Assembly is simple and straightforward, comprising essentially of putting together the wheel guards and tool rests.
This is a heavy, no-nonsense rig; do not expect it to be finely-machined and finished to a ’T.’
With more than enough power for DIYers and hobbyists, Lumberjack’s medium-duty grinder is an affordable option for light trade use too. Very robust and sturdy, it is an excellent value for money.
The BG250 measures 28 x 20.3 x 21.6 centimetres.
Lumberjack provides a one-year warranty.
- The 250-watt motor delivers very good torque and power.
- Remarkably sturdy and solid kit with a steel base is nearly free of vibrations.
- Best-in-class eye shields.
- The tool rests are on the small side; they could have been deeper and wider.
- The LED light can be improved.
A near-heavy-duty grinder that can be used by practicing tradesmen, Hilka’s grinder may have some quality control issues but it is most rugged and durable.
Hilka’s grinder comes with a coarse and a fine wheel and sports the most powerful motor among the bench grinders reviewed here, checking in at 1/2 horsepower – 370 watts. The wheels rotate at 3,000 RPMs no-load.
The tool rests are heavy-duty but rather small and narrow. They are adjustable along the front-to-back plane but adjustment is a fiddly nuisance as you have to use a spanner.
The eyeshields are good-sized and adjustable.
The 91600012 can exhibit marked differences from unit to unit; evidently quality control is not Hilka’s forte. Most units’ vibrations are imperceptible but a few throw uncomfortably palpable vibrations. Many units’ wheels run straight and true while a few units’ wheels exhibit some run-out or wobble.
That said, this is a no-fuss, durable power tool that can tolerate a bit of abuse and keep on going. It has a cast-aluminium body and the rig as a whole is not just rugged but obviously very powerful.
Weekend pros, as well as serious hobbyists, can use this medium-to-heavy-duty grinder not only for sharpening but also re-forming and re-shaping all metals, and for material removal.
It measures 32 x 40 x 23 centimetres.
Hilka provides a one-year warranty.
- Sporting a very muscular motor for a hobbyist’s kit, this one delivers serious torque.
- Rugged and powerful bench grinder can cope with hard-running use.
- Above average eye shields.
- Now and again a unit exhibits some or another defect due to spotty quality control.
- Adjustment of tool rests is comparatively fiddly.
How To Use A Bench Grinder To Sharpen Tools
A bench grinder is one of the more straightforward power tools to use, especially for sharpening tools, blades, and such. However, a bench grinder’s rapidly-spinning wheel poses a danger so be sure to put on goggles and work gloves. To avoid breathing in particulate matter, you should also wear a dust mask.
Note that some wheels are better than others for tool sharpening. Aluminium oxide wheels are better for iron and steel, and silicone carbide ones are better for aluminium, copper, etc.
Friable wheels are the preferred option for sharpening metals and the grit should be between 60 and 100.
• Keep a container of cool water nearby.
• Adjust the eyeshields.
• Turn on the bench grinder and allow the wheel to reach full speed. Hold the tool steady with the tip or edge to be sharpened resting on the tool rest and firmly touching, but not pushed against, the spinning wheel. For beveled tools like chisels, make sure that you hold the tool at the correct angle so as to work with and maintain the bevelling.
• If you let the tool lie on the rest or hold the tool’s edge or tip straight at the same track against the grinding wheel, you will probably wear a groove in the grinding wheel, burn the tool’s metal, or, most probably, end up doing both. Slowly and steadily move or swing the tool’s edge or tip from side to side.
• Keep the tool against the grinder’s wheel for no more than five seconds before removing the tool and putting the tip or edge inside cool water. This step is essential to avoid overheating and maintain the tempering and strength of the metal.
• Sharpen the tool only as much as necessary; take care not to oversharpen because this will degrade the strength of the tool. A good tip-off is the direction of the sparks. As long as a blunted tool is being sharpened, you will see sparks fly beneath the edge that is being sharpened. But at some point sparks will start to flow or roll over and around the upper side of the tool; when this occurs, you can conclude that your sharpening is nearly done.
How To Dress A Bench Grinder Wheel
To clean and unclog grinder wheels, and to expose new grit, you need to dress the wheel. To do so you need an inexpensive wheel dresser. It is a T-shaped tool comprising of a knurled cylindrical handle and a head with a diamond-and-metal-coated surface.
First wear goggles, work gloves and a dust mask, and adjust the eyeshields.
Turn on the bench grinder and allow the wheel to reach full speed.
With the dresser’s handle perpendicular to the wheel’s barrel, firmly hold the head flat against and evenly across the breadth of the wheel’s barrel.
As the wheel rotates, you will see it being cleaned and unclogged, and fresh grit appearing. Continue with the dressing until the wheel is evenly cleaned and an even coat of fresh grit is exposed such that the wheel looks like new. Remove the dresser and switch off the grinder.