What the MF-2718 is
This is a floor-standing universal tool grinder: a cast base cabinet, a vertical column, a swivelling wheel head on a belt drive, and a tool holder shaft on a cross slide below it. The wheel head tilts through 45 degrees either way, the table moves on two axes, and a segmented coolant hose points at the contact.
The Chinese name on the spec panel is universal tool grinding machine, and the panel lists what it is meant for: planer blades, saw blades, drill bits and small reamers. The English title calls it a knife sharpening machine, which is a translation of the word for cutter rather than a description of kitchen knives. It is a tool and cutter grinder, and that matters when you are searching for one.
It weighs 200 kg and the motor is under half a kilowatt. Both of those numbers are correct and they explain a lot about what the machine is for.
Nine rows, and not one of them is electrical
The parameter block carries nine technical rows: power, tool post rotating diameter, tool post stroke, wheel specification, wheel speed, wheel swivel, saw blade range, overall size and weight. There is no voltage, no phase, no frequency and no current.
For a machine that will be shipped at 200 kg and wired into a workshop, that is the largest hole in the specification. At 0.37 kW a 220 V single phase supply draws about 3.1 A and a 380 V three phase supply about 1.0 A, so either is easy to feed, but you cannot order the right one without being told which it is.
| Field | Parameter block | Spec panel in the images | Dimension drawing |
|---|---|---|---|
| Power | 0.41 kW | 0.37 kW | not shown |
| Wheel speed | 3500 r/min | 3600 r/min | not shown |
| Lifting height | absent | 200 mm | not shown |
| Length | 820 mm | not shown | 800 mm |
| Width | 630 mm | not shown | 700 mm |
| Height | 1250 mm | not shown | 1500 mm |
| Weight | 200 kg | 200 kg | not shown |
| Tool post envelope | 360 mm | 360 mm | not shown |
| Stroke | 280 mm | 280 mm | not shown |
| Wheel | 10 x 32(16) x 150 | 10 x 32(16) x 150 | not shown |
Four fields disagree across three sources, and one of them is only in the pictures.
0.37 or 0.41 kW is half a horsepower either way
The two figures look like a measurement error and are not. Converted, 0.37 kW is 0.496 horsepower and 0.41 kW is 0.550 horsepower. The ratio between them is 1.108, and the ratio between one half and 0.55 horsepower is 1.100.
So the discrepancy is exactly the step between a half horsepower motor and a 0.55 horsepower motor. Someone quoted the same motor in two conventions, or the machine is offered with two motors and both figures survived into the listing.
Practically the difference is 400 W against 370 W, which at the rim is 14.9 N against 13.1 N. Neither is a grinding force. But the label on the motor plate is what an inspector reads, and a machine whose documents disagree with its own plate is a problem at customs and at commissioning.
Wheel speed: 3500 or 3600, and what either gives at the rim
The number that matters is not the shaft speed but the rim speed, because that is what the wheel is rated for. For a 150 mm wheel it is the circumference times the revolutions.
| Shaft speed | Rim speed, 150 mm wheel | Share of the 35 m/s wheel rating |
|---|---|---|
| 2850 r/min | 22.4 m/s | 64% |
| 2974 r/min | 23.4 m/s | 67% |
| 3450 r/min | 27.1 m/s | 77% |
| 3500 r/min | 27.5 m/s | 79% |
| 3600 r/min | 28.3 m/s | 81% |
| 4358 r/min | 34.2 m/s | 98% |
At the two published figures the wheel runs at 27.5 or 28.3 metres per second. A standard vitrified bond straight wheel is rated at 35 metres per second, so either is comfortable at about 80% of the rating.
Note the top row of that table, because it is where this becomes a safety question rather than a cataloguing one.
Belt drive means your supply decides the wheel speed
The photographs show a long guard running from the spindle back to the motor, which is a belt guard. So the wheel speed is set by a pulley ratio and not by the motor's synchronous speed, and the same pulleys on a 50 Hz supply and a 60 Hz supply give different answers.
A two-pole motor runs about 2850 revolutions at 50 Hz and about 3450 at 60 Hz, a ratio of 1.21. Apply that to the published 3600 and the two possible machines are:
- set up for 50 Hz, so 60 Hz turns the wheel at 4358 r/min and the rim at 34.2 m/s, which is 98% of a 35 m/s wheel rating;
- set up for 60 Hz, so 50 Hz turns the wheel at 2974 r/min and the rim at 23.4 m/s.
That is a span from 23.4 to 34.2 metres per second on the same machine, and the top of it leaves no margin for a wheel that is rated at 35. Since no frequency is published anywhere, you cannot tell which machine you are buying.
The fix is one question and one number: ask for the pulley ratio and the rim speed at the wheel's discard diameter, and check the wheel you fit carries that figure on its blotter.
Thirteen newtons at the rim is a sharpening force
Half a kilowatt at 3600 revolutions is 0.98 newton metres, and at the 75 mm radius of a 150 mm wheel that is 13.1 newtons of tangential force. The 0.41 kW figure gives 14.9 newtons.
Thirteen newtons is roughly the push of a hand. That is not a criticism, it is the design intent: sharpening removes a few hundredths of a millimetre per tooth, and a machine that removes more than that per pass is a machine that burns edges.
What it does mean is that this is not the machine for restoring a chipped tooth or re-toothing a blade. Those jobs need ten times the force, and the motor will stall long before the wheel does.
The 360 mm head and the 500 mm blade
The tool post rotates within a stated diameter of 360 mm. The same table claims the machine will handle saw blades from 105 to 500 mm.
A 500 mm blade on a 360 mm head leaves 70 mm of blade hanging beyond the stated envelope on each side. The largest claimed blade is 39% wider than the head it is supposed to sit on.
There are two ways to read that and only the supplier can say which. Either 360 mm is the largest blade the indexing head will hold and the 500 mm figure refers to something else, or the head is not what limits the blade and the rotating diameter means something different.
For the smallest blade the numbers are comfortable: 105 mm is 29% of the head. So the lower end of the range is safe and the upper end is the open question.
In inches the range runs from about 4 to about 20, which covers a planer or a small mill but stops short of the 24 inch blades used on larger sawbenches.
The wheel is 150 by 10 by 32, with an 8 mm bush wall
The specification reads 10 x 32(16) x 150: 150 mm diameter, 10 mm thick, 32 mm bore, supplied with a bush down to 16 mm.
A 10 mm rim on a 150 mm wheel is a ratio of 1 to 15, which is a narrow wheel. That is right for sharpening, where you want to enter a gullet without rubbing the tooth either side, and it is wrong for any kind of form grinding.
The bush is the part nobody asks about. A 32 mm bore on a 16 mm spindle means the clamping load passes through an 8 mm wall sleeve. If that sleeve is a plain tube it will bell and the wheel will not run true; it should be a flanged bush that centres on the spindle shoulder. Ask which it is.
| Wheel diameter as it wears | Rim speed at 3600 r/min | Against a new wheel |
|---|---|---|
| 150 mm, new | 28.3 m/s | 100% |
| 140 mm | 26.4 m/s | 93% |
| 130 mm | 24.5 m/s | 87% |
| 120 mm | 22.6 m/s | 80% |
| 110 mm | 20.7 m/s | 73% |
| 100 mm | 18.8 m/s | 67% |
And the wheel slows as it wears. A 150 mm wheel taken down to 100 mm, which is a normal discard point, runs a third slower, and the finish and the cutting action change with it. If your process depends on a particular surface finish, that drift is part of the process and not a defect.
Green means silicon carbide, and that settles what it sharpens
The delivery photograph shows a wheel with a green face. Green is the conventional coding for green silicon carbide, the abrasive used on cemented carbide; aluminium oxide, usually grey, is the one for high speed steel.
That fits the title, which says cemented carbide saw blade, and it does not fit the rest of the description, which lists planer blades and drill bits. Carbide and HSS want different wheels, and running the wrong one either glazes the wheel or cracks the teeth.
So the wheel that arrives tells you what the machine was set up for, and if your work is HSS you should expect to buy a second wheel. No wheel grade, grit or hardness is published anywhere on the page.
The dimensions differ by 250 mm of height
| Dimension | Parameter block | Drawing | Difference |
|---|---|---|---|
| Length | 820 mm | 800 mm | 20 mm shorter on the drawing |
| Width | 630 mm | 700 mm | 70 mm wider, 11% |
| Height | 1250 mm | 1500 mm | 250 mm taller, 20% |
| Envelope | 0.646 m3 | 0.840 m3 | 30% more volume |
| Footprint | 0.517 m2 | 0.560 m2 | 8.4% more floor |
A quarter of a metre of height is not a rounding difference. It decides whether the machine goes through a doorway on a pallet, whether it fits under a bench that was measured for the smaller figure, and how many fit in a container.
Both envelopes weigh less than 200 kg volumetrically, so air freight is charged on the actual weight either way and the error does not cost you there. It costs you in floor planning and in the crate you quote to your own customer.
Ask for the crate dimensions rather than the machine dimensions. On a 200 kg machine the crate is what ships, and neither of these figures is it.
Two hundred kilograms on 0.37 kW
That is 541 kilograms per kilowatt, which is the signature of a cast base and a solid column rather than a folded frame. A machine that weighs this much for this little power is buying rigidity, and rigidity is exactly what a 45 degree indexing head on a 360 mm tool post needs.
The cost is freight and floor. The benefit is that the head does not deflect when the wheel loads up, which on a sharpening machine is the whole difference between a consistent edge and a tapered one.
It also means you should plan the lift. Two hundred kilograms at 1500 mm tall is not a two person job on a staircase.
There is coolant, and there is no coolant data
The photographs show a segmented hose aimed at the wheel, a drip tray extending past the base, and a cabinet door that is in exactly the place a coolant tank would be.
Nothing in the tables gives a tank volume, a pump power, a flow rate or a head. Sharpening carbide without coolant will micro-crack the edge, so this is not an accessory question.
The control station is on the column and carries a start button, a stop button and one rotary switch. The obvious reading is that the rotary switch runs the pump independently of the wheel, which is what you want, but it is a reading and not a statement.
What arrives in the crate
One photograph is laid out as a delivery kit and shows: two open ended spanners, a steel rule, a folding set of hex keys, a long pin spanner with a slotted bar, a drill chuck on an arbor, several loose arbors and bushes, a steady bracket, and one grinding wheel.
That is a usable starting kit for a tool grinder, and it is also not a list. Nothing states which arbor sizes, whether the chuck covers the drill range you need, or whether the wheel is the grade for your material. Ask for the packing list as a document, because a photograph of tools on a floor is not one.
Four checks before you wire it
These cost an hour and settle the four numbers this page could not.
- Read the motor plate. It will say the power, the voltage, the frequency and the speed, and that settles three of the four conflicts at once.
- Measure the rim speed or the shaft speed with a tachometer. Divide by the pulley ratio you can see, and compare against the 35 m/s wheel rating before you fit a wheel.
- Measure the machine, not the crate. Height is the field in dispute and it is the easiest to check.
- Mount a blade at the top of the claimed range and see whether the tool post indexes it cleanly at both ends of the 360 mm envelope.
Twelve questions for the quotation
| Question | Why it decides the order |
|---|---|
| What is the supply voltage, phase and frequency | None of the three is published, on a 200 kg export machine |
| Is the motor 0.37 kW or 0.41 kW | The block and the panel differ by exactly the half to 0.55 horsepower step |
| Is the wheel speed 3500 or 3600 r/min, and at which frequency | Belt drive means the number is a pulley ratio, so it is meaningless without the frequency |
| What is the pulley ratio, and what is the rim speed at the wheel's discard diameter | Rim speed falls 33% as a 150 mm wheel wears to 100 mm |
| What is the enclosure box height, 1250 or 1500 mm | Two hundred and fifty millimetres between the block and the drawing |
| Which wheel bond ships, and is it rated for the top rim speed | A 35 m/s vitrified wheel is at 98% of its rating if the machine runs 20% fast |
| What blade diameter will the tool post actually index | 360 mm envelope against a 500 mm capability claim |
| Is the 16 mm bush a flanged bush or a plain sleeve | The wheel bore is 32 mm on a 16 mm spindle, so the bush carries the clamping load |
| What is the coolant tank volume, pump power and flow | Coolant is visible in the photographs and absent from every table |
| What is the motor protection class and insulation grade | Coolant and grinding dust together decide motor life |
| What is the exact list of tooling in the crate | The delivery photograph shows a chuck, arbors, spanners and one wheel, with no list |
| Is there a guard interlock or a no-volt release | The control station has start, stop and one rotary switch, and nothing is stated |
Where this sits with the other sharpening pages
The MF206 planer blade sharpener guide covers the straight knife machine, which is the right tool if all you sharpen is planer and jointer knives up to 650 mm; that machine grinds a straight edge on a travelling table, while this one indexes a rotating cutter. They are complementary rather than alternatives, and a workshop doing both usually ends up with one of each.
Frequently asked questions
Is this a knife sharpener or a tool grinder?
A tool and cutter grinder. The Chinese name translates as universal tool grinding machine and the spec panel lists planer blades, saw blades, drill bits and small reamers. The English title says knife, which is a translation of the word for cutter and misleads anyone looking for a kitchen knife sharpener.
Why does the listing give two different power figures?
0.37 kW is 0.496 horsepower and 0.41 kW is 0.550 horsepower, and the ratio between them, 1.108, matches the ratio between a half and 0.55 horsepower almost exactly. The block and the spec panel are quoting the same motor in two conventions, or two different motor options. Read the motor plate to settle it.
What rim speed does a 150 mm wheel run at?
At 3500 revolutions it is 27.5 metres per second and at 3600 it is 28.3, both about 80% of the 35 m/s rating of a standard vitrified wheel. But the drive is by belt, so the speed follows the pulley ratio, and the same machine on 50 Hz and 60 Hz supplies can span 23.4 to 34.2 metres per second.
Can it really sharpen a 500 mm blade?
The tool post rotates within a stated 360 mm diameter, which leaves 70 mm of a 500 mm blade beyond the envelope on each side. Either 360 mm is the real limit and the 500 mm figure means something else, or the rotating diameter does not describe the blade capacity. Mount one before you commit.
Will it remove a broken tooth?
No. Half a kilowatt at 3600 revolutions gives about 13 newtons at the rim, which is roughly hand pressure. That suits taking a few hundredths of a millimetre off each tooth. Re-toothing needs an order of magnitude more force and the motor will stall.
What wheel should I fit?
The wheel shown in the delivery kit is green, which is the usual coding for green silicon carbide and the grade for cemented carbide. For high speed steel you want aluminium oxide instead. No grit, grade or hardness is published, so specify the wheel yourself and check its rated speed against the rim speed you measure.
Is the coolant pump included?
The hose, the drip tray and a cabinet in the position a tank would occupy all appear in the photographs, and no tank volume, pump power or flow rate is published anywhere. The extra rotary switch on the control station probably runs the pump. Treat it as a question, not an assumption.
Key specifications
Frequently asked questions
- Is this a knife sharpener or a tool grinder?
- A tool and cutter grinder. The Chinese name translates as universal tool grinding machine and the spec panel lists planer blades, saw blades, drill bits and small reamers. The English title says knife, which is a translation of the word for cutter and misleads anyone looking for a kitchen knife sharpener.
- Why does the listing give two different power figures?
- 0.37 kW is 0.496 horsepower and 0.41 kW is 0.550 horsepower, and the ratio between them, 1.108, matches the ratio between a half and 0.55 horsepower almost exactly. The block and the spec panel are quoting the same motor in two conventions, or two different motor options. Read the motor plate to settle it.
- What rim speed does a 150 mm wheel run at?
- At 3500 revolutions it is 27.5 metres per second and at 3600 it is 28.3, both about 80% of the 35 m/s rating of a standard vitrified wheel. But the drive is by belt, so the speed follows the pulley ratio, and the same machine on 50 Hz and 60 Hz supplies can span 23.4 to 34.2 metres per second.
- Can it really sharpen a 500 mm blade?
- The tool post rotates within a stated 360 mm diameter, which leaves 70 mm of a 500 mm blade beyond the envelope on each side. Either 360 mm is the real limit and the 500 mm figure means something else, or the rotating diameter does not describe the blade capacity. Mount one before you commit.
- Will it remove a broken tooth?
- No. Half a kilowatt at 3600 revolutions gives about 13 newtons at the rim, which is roughly hand pressure. That suits taking a few hundredths of a millimetre off each tooth. Re-toothing needs an order of magnitude more force and the motor will stall.
- What wheel should I fit?
- The wheel shown in the delivery kit is green, which is the usual coding for green silicon carbide and the grade for cemented carbide. For high speed steel you want aluminium oxide instead. No grit, grade or hardness is published, so specify the wheel yourself and check its rated speed against the rim speed you measure.
- Is the coolant pump included?
- The hose, the drip tray and a cabinet in the position a tank would occupy all appear in the photographs, and no tank volume, pump power or flow rate is published anywhere. The extra rotary switch on the control station probably runs the pump. Treat it as a question, not an assumption.