Notched vs Plain Disc: Which Harrow Disc Blade for Your Field?

Notched vs plain disc is one of the first questions buyers ask when they order harrow discs. The two blades look similar, but they cut soil and residue in different ways. Choosing the right edge for each gang gives a better seedbed with fewer passes. This guide explains the difference and how to combine them on one harrow.

What Is a Notched Harrow Disc?

A notched harrow disc, also called a scalloped disc blade or cut-out disc, has evenly spaced notches around its edge. The notches act like teeth:

• They grip the soil and pull the disc into hard ground.
• They chop long stalks, roots and heavy residue such as corn stalks and sugarcane trash.
• They keep the disc turning when the ground is trashy, so it does not skid.

What Is a Plain Disc Blade?

A plain disc blade has a smooth, continuous edge. It slices cleanly and leaves a smoother, more level finish. Plain discs are common on the rear gang of a harrow and on disc ploughs, ridgers and seed drills, where an even cut matters more than biting into residue.

Notched vs Plain Disc: 5 Key Differences

Point	Notched disc	Plain disc
Penetration	Bites into hard, dry ground	Needs more weight to enter hard ground
Residue	Chops stalks and roots	Can ride over heavy residue
Finish	Rougher	Smoother, more level
Typical position	Front gang	Rear gang, ploughs, ridgers, seeders
Sharpening	Normally replaced	Can be re-sharpened

Front Gang Disc and Rear Gang: the Usual Combination

Most tandem and offset harrows use a notched front gang disc to cut residue and open hard ground, and a plain rear gang to level and finish. For light, clean soil some farmers use plain discs on both gangs; for very heavy residue, notched discs on both gangs can help. Our disc harrow size chart shows typical disc sizes for each harrow, and the heavy duty disc harrow guide covers offset harrows.

Notched vs Plain Disc by Crop and Season

After a corn or sorghum harvest, thick stalks lie on the field. Here a notched front gang cuts and mixes residue so it breaks down faster and does not block the seeder later. In sugarcane areas, notched blades on heavy harrows are standard for breaking up trash and old stools. After a light crop such as beans or wheat, or on land that was already ploughed, plain discs on both gangs can be enough and leave a smoother seedbed. In the dry season, hard ground favours notched discs for penetration; in moist, friable soil, plain discs work well and wear evenly. Many farmers keep one set of each and change gangs for the season.

Sizes and Materials

We make both edge types from 12 to 36 inches and 3 to 12 mm thick, in 65Mn or 30MnB5 boron steel, heat-treated to HRC 38–44, with square or round centre holes. Notched blades weigh slightly less than plain blades of the same size because of the cut-outs. Full weight tables are on our harrow discs page.

How to Choose for Your Field

• Heavy residue (corn, sugarcane, sorghum): notched front gang.
• Hard, dry or virgin ground: notched discs help penetration.
• Final seedbed preparation: plain discs for a smoother finish.
• Stony ground: choose thicker blades and boron steel; notches can chip on large stones.

Good tillage choices save passes and fuel, in line with the FAO’s work on sustainable agricultural mechanization.

FAQ

Can I put notched discs on both gangs?

Yes, for very heavy residue. The finish will be rougher, so a lighter second pass may be needed.

Is a scalloped disc blade the same as a notched disc?

Yes. Scalloped, notched and cut-out disc are different names for the same blade.

Do plain disc blades last longer?

Life depends mostly on steel, hardness and soil. Plain blades can be re-sharpened; notched blades are normally replaced.

Which disc goes on a disc plough?

Disc ploughs normally use plain blades with deeper concavity. See our plough disc blades guide.

Get a Quote

Send diameter, thickness, edge type, centre hole, steel grade, quantity and destination port on WhatsApp +86 133 8469 2372, or see all sizes on the harrow discs page and complete harrows.