Disc Mower Blade – Frequently Asked FAQs
1 What is a disc mower?

The first-ever agriculture equipment to hit the hay fields are disc mowers.
Disc mowers provide their services in cutting or mowing forage with stalk/hay, underbrush, and the like, and it refers mainly to a tractor type mower.
These mowers feature spinning discs with small hinged blades on the outside edges.
The discs drive by gears or shafts that are present inside the cuter bar.
This tractor-type mower has cutting elements of the horizontal whirling blade type.
The location of cutting elements is such that to extend laterally beyond the vertical wheel planes of the outermost wheels.
It allows easy access to space under overhanging branches located near to the ground.
It also makes it possible to cut closely adjacent trees or walls.
Figure 1 John Deere disc mower
Another purpose of disc mowers is to provide horizontal blade mower, and the operator is guarded against the flying fragments of rock or other articles.
These fragments or small stones might get caught in the disc mower blades.
In disc mowers, disc mower blades are mounted on several small discs that rotate rapidly on the top of a cutter bar.
Disc mower blades don’t move back and forth on the cutter bar in disc mowers.
The invention of disc mowers was a progression from the sickle bar design.
Disc mowers have multiple mower-conditioner heads; it relates to a framing mechanism that helps in repositioning the heads.
The heads should place between transport and operating configurations.
2 What is a disc mower blade?

Disc mower blades are the cutting elements of the disc mowers.
These disc mower blades are made of strong metals; these durable metals enable them to tolerate quick contact with different components while mowing.
The size, design and thickness of the disc mower blades depend upon different requirements and the agriculture parts suppliers.
The length of the cutting blade has to be more than 70mm.
The width of the disc mower blades cutting blade has to be more than 35mm measured at 10 mm from the disc.
For a boring of 21mm, the pitch of the screw should not be ovalized more than 23mm.
It must make sure that all of the new disc mower blades must have the same length.
The primary functions that the disc mower blades must satisfy are:
- Cutting
- Mowing
- Cleaning
- Outflowing crops evenly
Figure 2 Disc mower blades
Some disc mower blades deliver all the tasks while others only perform any one of the functions mentioned above.
Disc mowers configure to use such disc mower blades that correspond to their measurements and holes configurations.
These disc mower blades are inexpensive and easy to change, can be quickly removed and disconnected from the tractor without affecting the operation of the blade on the other side.
The operation finds particular advantage where it is a desire to cut on only one side of the mower.
3 How to sharpen disc mower blades?
Disc mower blades that remain sharp and damage free don’t require regular replacements.
A standard disc mower blade is sharpened several times throughout the course of its life for its proper working.
Some of the following points must be taken into account while sharpening the disc mower blades:
- To maintain the angle of the original cutting edge, grind the disc mower blades top surface only.
- If the bottom surface is to be ground, it will make the disc mower blade a chisel.
- The cutting edge of the disc mower blade must be in contact with the grass surface to get a clean cut; otherwise, it will rag the grass.
Some combine harvester parts manufacturers also supply these blades based on the requirements of the customers.
If the disc mower blades get thin or weak, then replace them immediately with new ones.
Disc mower blade suppliers make blades as per the requirement of their customers, and they use high carbon steel for manufacturing these disc mower blades.
Whenever we want to remove a disc mower blade for sharpening:
- The balance of the blade must be check whenever a blade is removed for sharpening.
- It must make sure that the disc mower blade is not bent and has an appropriate attitude relating to the ground surface and the housing.
- It should make sure that the disc mower blade nuts or bolts are tightened correctly to the right torque while installing the blades again after sharpening.
- The disc mower blades must be sharpened correctly.
Figure 3 Sharpening disc mower blades
If the mowing process keeps going with the damaged disc mower blades, then these disc mower blades can break and might harm the nearby people as the metal components can fly out.
The continuous use of disc mower blades can make them dull and blunt, so proper maintenance and replacement are required.
Other factors, such as rocks, debris, and sand, can also damage the disc mower blades.
4 How do you cut hay with disc mower blades?

The purpose of haymaking is to capture all the nutrients present in the grass in the stored form to use it in the winter season.
The determining factor that initiates the mowing of the first field of the season is the maturity of the grass.
The disc mowers can mow through the thick hay very well, and the whole operation can take place at higher speeds than the conventional mowers.
For depositing the hay in a swath, disc mower can also be outfitted with a crimper.
The disc mowers provide an industry-leading cut and crimp for superior quality hay for your customers or livestock.
https://www.youtube.com/watch?v=6222obgNb8E
5 How fast can you mow with disc mower?
The disc mowers give maximum mowing capacity in the fields.
Disc mowers can cut or mow lodged and thick hay easily.
There is almost no limit to how fast one can mow with the help of disc mower
According to the comparison between mowing capacities of swathers, drum mowers, and disc mowers, disc mower performed more effectively.
Type of Mower |
Time-taken |
Drum mower |
01:59:14 |
Disc mower |
01:49:85 |
The field used for this test contained conventional alfalfa and some decent grass.
Speed of Disc mowers:
10 mph – easily achievable by a mid-sized utility tractor with a disc or drum mower.
Assumption:
It has the horsepower.
15 mph – this speed is feasible with a large tractor and disc mower.
Probably too fast to be safe for smaller components.
It feels like disc mower has a flight in the hayfield.
Adjustment of height of mower from the ground:
Lift the mower some centimeters after hitching it to the tractor.
Then lower the mower in the work position, some centimeters above the surface of the ground.
6 What are the best disc mower blades?

The best disc mower is The Massey Ferguson DM 306 P that is available in the rear and side-mounted category.
The discs of this disc mower are powered through the PTO through a V-belt.
The gears mounted inside the cutter bar drive the discs.
It leaves the hayfield like a yard after mowing all the hay and forage.
The best cutting blades are the self-sharpening cutting blades.
They provide high quality cutting as the blade wears.
The self-sharpening blades are:
- Inexpensive to use
- Durable of construction
- Easy to maintain
- Effective to use
The apex of these disc mower blades is of the harder material than the rest of the blade, so by the time, the softer part gets duller than, the harder part which maintains the cutting edge.
The self-sharpening characteristics of the cutting blade are obtained by treating a blade in a way that creates a hardened portion of the blade thickness, also known as the gradient.
7 What are the benefits of keeping the disc mower blade sharp?
Sharp disc mower blades give an excellent and neat cut whereas dull blades can damage the grass and also deteriorate the field.
It provides a quick cut and maintains the best quality cut.
It does not require any time to change the dull disc mower blades in the disc mowers so there must be no excuses in sharpening the blades.
Sharp disc mower blades are essential for maintaining the health of the grass on the ground.
The sharper the disc mower blades are, the more quality cut one will get.
Sharp disc mower blades do not damage the field, they cut the hay or forage thoroughly from their ends.
Less crop is left behind by using sharp disc mower blades.
Sharp disc mower blades demand less time for mowing than dull blades.
The main benefit of having sharp disc mower blades is they can cut the rough fields, like a field having wild alfalfa and wild hay, and leave the field extremely fine.
All kinds of disc mower blades require sharpening and maintenance whether it is the Kubota harvester blade, combine harvester blade or a disc mower blade.
8 What are the types of disc mower blades?
The disc mowers that are most commonly used are tractor-type mowers.
It is compact in construction and simple to operate.
After the removal of cutting blades, the tractor is a conventional vehicle that can serve other purposes too.
Features of tractor-type mower:
The disc mower blade housings are extended laterally from each side of the tractor which forms a flat platform.
The spaced rods are present on the leading edge of each housing, giving a grill-like appearance to the housings.
The horizontal blade arms are present at the lower end of the blade shaft.
The housing has enough space in it that the blades rotate wholly with its arms in it.
The grass or other small components get entry into the housings through grill rods.
No uncut swaths are left within the housings.
The disc mower blades operate well over rough and uneven terrain.
As the wheels ride over the uneven surface containing ridges and hollows, the outer-board parts of the housings rise and dip well cutting the field evenly.
When the tractor operates on the rough surface, the hinge connections and the wheels prevent digging in of housings and blades.
The disc mower blade housings can be removed; housings can be lifted by hands to slacken the belts.
Different types of disc mower blades are available for different kinds of crops in the market:
- Rock blades or knives have a different shape than all other cutting knives or blades
It has a curved surface and is used when the condition of the field is terrible.
Rock knives deal with the rocks and stones in the field efficiently and prevent any crop damage.
- Standard knives or blades – 14 degrees, a shallower knife is going to cut a shallower crop better.
These knives create less wind off of the blades by spinning around at that shallower pitch.
These knives are generally best for your everyday crop.
- Serrated knives or blades help in mowing light crops.
These knives have cuts or ridges at each edge.
These serrations help them to hold the crop a little longer and cut more efficiently.
9 How can I make my mower blade last longer?
Disc mower blades require regular maintenance to work correctly.
To help keep your disc mower blades lasting as long as possible, here are a couple of pointers:
- Sharpen the disc mower blades on time and remember to replace them when you see a bend in the blade.
- Remove long stalks or big rocks from the fields if you can see them through naked eyes so that they may not damage your disc mower blades.
- After every mowing operation, check your disc mower blades whether they need to get sharper.
- Not only focus on just sharpening the disc mower blades but also replace them with the new one if required.
Figure 4 Disc mower blades on a cutter bar
- In case of an accident, read the manual or get help through the manufacturers of these disc mower blades.
- After sharpening or replacing the disc mower blades, assemble them correctly.
- Check the orientation of other components, if they are not in place, then repair them too.
- Clean the inside of the mower as small rocks or soil get entry into the mowers and may cause difficulty in proper functioning.
All the disc mower blades can be made to last longer by proper maintenance and time-to-time replacement.
The new disc mower blades are required to be prepared for a replacement for every season, whatever you u using a combine harvester like John Deer or a Kubota harvester.
10 How to change disc mower blades?

Disc mower blades provide better outflow of crops for better drying.
But there is always a need to sharpen or replace the disc mower blades like the Kubota harvester parts which also require proper maintenance.
Changing disc mower blades is not a big deal in modern disc mowers.
The tool used for replacing disc mower blades comes pinned on the machine.
With the help of the tool, you can easily open the bolt or nut and remove the wear disc mower blades by only using your hand.
Get a new disc mower blade, keep it in place, and fasten the bolt again.
One thing that should be kept in mind is that the new disc mower blades must have the same length as the older one.
The specifications of the disc mower blades can only be the same if you buy them from the same Disc mower blade manufacturers.
11 What is a disc mower conditioner?
The farming land is increasing day by day to meet the required output.
As we all know that mowing periods are limited, and the production of top-quality of forage is necessary, therefore:
Disc mower conditioners provide top-notch performance and meet all the requirements.
Many economical mowers are also present in the agriculture industry for farmers.
Disc mower conditioner does hard work a little bit easier and has the most advanced specifications:
- Precise conditioning
- Easy maintenance
- Multiple windrow adjustments
- High output
- Quality cut
Disc mower conditioners offer the best cutting and conditioning.
These conditioners offer ease of adjustment and versatility and are capable of matching the fluctuating field conditions.
The conditioner cuts and crimps newly cut hay to let it dry more quickly.
The two grooved rollers are present in conditioners through which the hay is forced.
These grooved rollers cause the stalks to split and the forage to dry more.
The stand-alone conditioner was used in the past, but now the conditioner is incorporated into mower conditioners.
Conditioners work with more power and precision and leave the field even thoroughly.
12 What are the applications of disc mower blades?
The disc mower blades pull the grass a little bit better hold it for long rather than just letting it slip over the surface.
The disc mower blades mow efficiently through the lush hay fields.
These disc mower blades mow almost all the crop and leave nothing behind on the field.
These disc mower blades can be applied to any type of field, either it may be rough and terrible or even have properly grown grass.
The disc mower blades can be changed depending upon the field and the crop.
13 How is a disc mower maintained?
Disc mowers must be maintained at times to keep them functioning.
Different disc mowers require different maintenance techniques, for example, the following is the maintenance routine of a rotating disc mower:
Time-frames |
Lubricate/Grease/Run a check |
Every 8 hours |
-Grease the vertical crank
-Grease the universal joint spider
-Grease the axis of the beam
-Check on wear & tear of cutters |
Every 20 hours |
Grease all the extension tubes of the universal joint spider |
Every 40 hours |
Check the following:
-the gearbox
-the cutting blade
-oil the fork pin
-grease safety release blades |
After the first 8 hours |
Make sure that all the screws are tightened especially screws of the cutter |
After the first 50 hours |
Change the oil of reduction gear and cutting blades |
After each session |
Change Oil in:
-cutting blade
-reduction gear
-check all the cutter blades |
In case of accidents, the maintenance routine must be:
Accidents |
Possible causes |
Remedies/Solutions |
Left out cutting traces |
Power take-off turns are working slowly that prevents the cutters from doing their work |
It usually happens on sloping the land. Make sure that the power take-off does not diminish. |
Left out mowing traces |
The insufficient inclination of blades |
Check the inclination level of blades |
Heating up of the blade |
Excessive oil in blades
Unsuitable oil |
Check the oil level to remove excessive oil
Replace with prescribed oil |
Irregular height of cutting |
Cutters worn
Traveling speed too low
Power take-off turns are too slow |
Replace cutters
Increase work speed
Make sure that the speed of power take-off is regular |
Belts slip |
Spring is not compressed sufficiently |
Tighten the turnbuckle screw to compress the spring |
The mower is not leveled |
The hoisting piston has not run a full course |
_ |
Irregular cut |
The backward leaning of the machine |
Check the machine |
14 What are the differences between lawnmower blades and disc mower blades?

The primary difference between lawnmower blades and disc mower blades is the shape.
Lawnmower blades have diversity in them and come in different shapes depending upon their job while disc mower blades have a standard configuration.
Lawnmower blades include mulching blades and regular blades.
Mulching blades are all-purpose kind of knives that offer all the three basic operations, lifting, mowing, and mulching.
Figure 5 Disc mower mowing a field
Mulching blades cut the clippings into smaller pieces.
Regular lawn mower blades perform two functions; usually, they can discharge grass clippings through mowers side-discharge chute.
While the disc mowers are for mowing hayfields where they cut, mow hay, and leave the field even thoroughly.
15 When is the disc mower the right choice for your operation?
Disc mowers must be maintained and ready-to-go when the grass or hay is ready to cut.
Disc mowers play their roles in hay season where every bit of time is saved by using disc mowers, and it also saves a lot of money.
They can even work on hillsides with 100% efficiency and provides the farm owners with a top-notch hay cut.
Figure 6 Kubota disc mower mowing a lush field
The disc mowers meet the 99% needs of the people who own a compact or sub-compact tractor.
Decisions are to be made quickly during hay season to accomplish one task after another, mowing, raking, baling.
The repair costs are low, and disc mower blades are also replaceable.
The price of disc mower blades is also economical.
The features of disc mowers are time-saving while mowing more than one field.
There is always an ease of transition as the hydraulic lifts allow us to go from working to transport and then back to work within no time.
The optimum speed is 15mph that is attainable if you’re using horsepowers, though very few tractors offer this speed.
Disc mower blades can cut and handle thick-lodged hay or forage with stalks efficiently.
16 What measures should be taken before storing the disc mower in winter?
We recommend to take the following measures before keeping the mower away for the winter season:
- Perform all the lubrications inside all parts of the mower.
- Grease all the screws, nuts, and bolts of the disc mower blades.
- Clean the exterior part of the cutter bar thoroughly.
- Cover the disc mower with a plastic tarpaulin.
- Loosen the v-belts (for rotary disc mowers).
- Store the disc mower in a dry place.