Heavy Duty Disc Harrow Guide: How Offset Hydraulic Disc Harrows Handle Tough Soil

A heavy duty disc harrow is one of the most powerful tillage tools a farm can own. It cuts through hard ground, chops thick crop residue, breaks big clods and levels the field in one pass. On many farms it even replaces the plough.

This guide explains how a heavy offset disc harrow works, where it performs best, how it compares with other harrows and ploughs, and how to choose the right size for your tractor.

What Is a Heavy Duty Disc Harrow?

A heavy duty disc harrow is a trailed implement with two gangs of large, concave steel discs mounted on a strong, rigid frame. Most models are offset disc harrows: the front and rear gangs are arranged in a V shape and set to one side of the tractor’s centre line.

The harrow rides on hydraulic transport wheels. A hydraulic cylinder lowers the discs into work, controls depth, and lifts the harrow for turning and road transport. Typical machines use 660 mm (26″) notched or plain discs, a working depth of about 15–20 cm, and weigh well over a tonne, which gives strong penetration.

What Is It Used For?

• Primary tillage on cultivated land, in place of a plough.
• Breaking hard, compacted surfaces and dry crusts.
• Chopping and mixing crop residue such as corn stalks, sugarcane trash and straw into the soil.
• Opening new or weedy land and pasture renovation.
• Crushing clods after ploughing and levelling the seedbed.
• Preserving soil moisture by breaking capillaries at the surface

How Does an Offset Disc Harrow Work?

1. The tractor pulls the harrow by its drawbar hitch.
2. The front gang throws soil in one direction; the rear gang throws it back, leaving the field level.
3. The angle between the gangs makes the discs cut, lift and turn the soil.
4. The heavy frame weight pushes the discs deep into hard ground.
5. Sealed bearings on square gang shafts keep the discs turning smoothly in dust and mud.
6. The operator lifts the hydraulic wheels at headlands and for transport.

Key Advantages

• Strong penetration in clay, dry and compacted soils thanks to the heavy frame.
• One pass does several jobs: cutting, mixing, crushing and levelling.
• High work rate: wide working width and fast forward speed compared with a plough.
• No blockage in heavy trash; discs roll and cut through residue.
• Easy transport on hydraulic wheels, small turning radius.
• Low maintenance: sealed bearings and simple, rugged construction.

Offset vs Tandem Disc Harrow, and Harrow vs Plough

Feature	Heavy Offset Disc Harrow	Tandem (Opposed) Disc Harrow	Disc Plough
Disc layout	2 gangs in a V, offset	4 gangs in an X	Individual discs on standards
Weight and penetration	Very high	Medium	High
Working depth	15–20 cm	8–15 cm	25–30 cm
Work speed and width	Fast, wide	Fast, wide	Slower, narrow
Best job	Primary tillage, heavy residue, hard soil	Seedbed preparation, secondary tillage	Deep inversion, virgin land
Tractor size	70–160+ HP	30–160 HP	40–160 HP

Our advice: for hard soil and heavy residue, a heavy offset disc harrow gives the fastest results. For final seedbed preparation, use a lighter tandem harrow. For deep ploughing or virgin land with roots, start with a disc plough and finish with a harrow.

How to Choose the Right Size

Match the number of discs and the working width to your tractor’s horsepower. Typical heavy duty disc harrow sizes with 660 mm discs:

Model	Discs	Working Width	Working Depth	Weight	Tractor Power
SH-1BZ-2.2	20	2.2 m	15–20 cm	approx. 1,350 kg	80–100 HP
SH-1BZ-2.5	24	2.5 m	15–20 cm	approx. 1,450 kg	90–100 HP
SH-1BZ-3.0	28	3.0 m	15–20 cm	approx. 1,550 kg	100–120 HP
SH-1BZ-3.4	32	3.4 m	15–20 cm	approx. 1,750 kg	120–140 HP
SH-1BZ-4.0	36	4.0 m	15–20 cm	approx. 1,950 kg	140–160 HP

All models: trailed, hydraulic lift transport wheels, 660 mm discs. Figures are typical; check the product spec sheet for exact values.

Notched or plain discs?

• Notched (cutaway) discs on the front gang cut through heavy residue and penetrate hard ground better.
• Plain discs on the rear gang give a smoother, more level finish.
• Many farmers choose notched front + plain rear for the best of both.

Questions to ask before you buy

• What is your tractor’s horsepower and does it have rear hydraulic outlets?
• Do you work heavy clay, sandy soil, or sugarcane/corn residue?
• Will the harrow replace your plough, or follow it?
• How far do you need to transport it between fields?

Maintenance Tips

1. Grease the bearings every 8–10 working hours (or daily in dusty conditions).
2. Check gang bolts and nuts after the first day of work, then weekly.
3. Inspect hydraulic hoses and cylinder for leaks before each season.
4. Replace worn or cracked discs promptly to keep the cut even.
5. Check tyre pressure on the transport wheels.
6. Clean, oil and store under cover after the season to prevent rust.

Related guide: our disc harrow size chart for 12–80 hp tractors compares light and medium mounted harrows if your tractor is under 80 hp.

Related guide: Heavy disc harrow vs disc plough: which is better for your farm?

Frequently Asked Questions

What horsepower do I need for a heavy duty disc harrow?

A 20-disc, 2.2 m heavy harrow typically needs 80–100 HP. A 28-disc, 3.0 m model needs about 100–120 HP, and a 36-disc, 4.0 m model 140–160 HP.

Can a heavy disc harrow replace a plough?

On cultivated land, often yes. A heavy offset harrow cuts, mixes and loosens the top 15–20 cm in fewer passes. For deep inversion or virgin land with roots, a plough is still better.

What is the difference between an offset and a tandem disc harrow?

An offset harrow has two gangs in a V and is heavier, built for primary tillage. A tandem harrow has four gangs in an X and is used mainly for seedbed preparation.

Should I choose notched or plain discs?

Notched discs penetrate and cut residue better; plain discs leave a smoother finish. A combination of notched front and plain rear is common.

Is a heavy disc harrow good for clay soil?

Yes. Its weight and large discs give strong penetration in heavy and sticky clay where lighter harrows ride on top.

What is a hydraulic disc harrow?

A hydraulic disc harrow uses a hydraulic cylinder to lower the gangs into work, control depth and lift the harrow onto its transport wheels. All our heavy offset models are hydraulic disc harrows, so your tractor needs a rear hydraulic outlet.

How do I choose a tractor disc harrow for my horsepower?

Match the tractor disc harrow width to power: about 80–100 HP for a 2.2 m, 20-disc model, 100–120 HP for 3.0 m, and 140–160 HP for 4.0 m. For smaller tractors, choose a light or medium harrow from our harrows range.

See all sizes on our harrows page. For background, the FAO explains how the right equipment supports sustainable agricultural mechanization.

Buy Heavy Duty Disc Harrows Direct from the Factory

ShengHang manufactures hydraulic heavy duty offset disc harrows from 20 to 36 discs, along with light, medium and folding harrows, harrow discs, ploughs and tractors. We ship worldwide by sea, rail and air from Shandong, China.

Need a quote or help choosing a model? Contact Lucas Xu on WhatsApp +86-13384692372 or email xsh13384692372@gmail.com. Tell us your tractor power, soil type and crop, and we will recommend the right disc harrow for your farm.