Disc Harrow Size Chart: Light vs Medium Harrows for 12–80 HP Tractors

Picking the right disc harrow size is mostly about your tractor: too small and you waste time, too big and the tractor slips, overheats or cannot lift the harrow. This guide explains the difference between light and medium mounted harrows, gives a simple chart from 12 to 80 hp, and shows how to choose discs, width and depth for your soil.

What a Disc Harrow Does After Ploughing

After ploughing, the field is rough with clods and buried stubble. A disc harrow has two gangs of concave discs set at an angle. As the tractor pulls it, the discs roll, cut residue, break clods and mix the topsoil. One or two passes leave a level seedbed ready for a seeder or planter.

Shenghang makes five harrow series. This disc harrow size guide covers the two three-point mounted series for small and mid-size tractors. For tractors over 80 hp, read our heavy-duty disc harrow guide.

Light Disc Harrow vs Medium Disc Harrow

Point	Light series (1SH-L)	Medium series (1SH-M)
Disc diameter	460 mm	560 mm
Number of discs	12–24	10–26
Working width	1.1–2.3 m	1.1–2.8 m
Working depth	100–140 mm	140 mm
Weight	200–420 kg	320–700 kg
Tractor power	12–55 hp	25–80 hp
Best for	Light and sandy soil, small farms	Mixed farms, loam and heavier soil

The medium harrow uses bigger discs and is heavier for the same width, so it cuts deeper and works better in clay and heavy stubble. The light harrow is the 3 point disc harrow to choose when the tractor is small or the soil is easy.

Disc Harrow Size Chart by Tractor HP

Tractor (hp)	Light model	Medium model
12–18	1SH-L1.1 (1.1 m, 12 discs)	–
20–25	1SH-L1.5 (1.5 m, 16 discs)	–
25–30	1SH-L1.7 (1.7 m, 18 discs)	1SH-M1.1 (1.1 m, 10 discs)
35–40	1SH-L2.0 (2.0 m, 20 discs)	1SH-M1.3 / M1.5
40–45	1SH-L2.2 (2.2 m, 22 discs)	1SH-M1.5 / M1.7
50–60	1SH-L2.3 (2.3 m, 24 discs, 55 hp)	1SH-M2.0 / M2.2
65–80	–	1SH-M2.4 / M2.5 / M2.8

Getting the disc harrow size right is simple: use the lower model in your band for heavy, wet or stony soil, and the upper model for light, dry soil. Full tables are on our harrows page.

How to Choose a Disc Harrow for a Small Tractor

A light disc harrow is usually the right 3 point disc harrow for 12–55 hp, while a medium disc harrow suits 25–80 hp and harder soil.

• Check lift capacity. A mounted harrow hangs on the three-point linkage. Make sure the tractor can lift it with some margin.
• Match width to wheel track. The harrow should cover the tractor wheel marks so they are loosened in the same pass.
• Think about soil. In clay, a smaller medium harrow often beats a wider light harrow.
• Plan your line. A plough first, then the harrow, then a seeder. A rotary tiller can replace both plough and harrow on small plots.

Not sure? Use our selection assistant or send us your tractor model.

Setup and Field Tips

1. Level the harrow with the top link so both gangs work at the same depth.
2. Set a moderate gang angle; a larger angle cuts deeper but needs more power.
3. Work across the plough furrows for faster levelling.
4. Do not harrow very wet soil – it makes smeared, hard clods.
5. Keep speed steady; too fast and the harrow bounces.

Reducing passes saves fuel and protects soil structure, one of the aims of sustainable agricultural mechanization promoted by the FAO.

Maintenance and Spare Discs

• Grease gang bearings before each working day.
• Check that gang bolts are tight; loose gangs wear discs and bearings fast.
• Replace discs when the diameter has worn down noticeably or the edge is chipped.
• Clean soil off the frame and oil the discs before storage.

We also supply replacement discs in plain and notched types. See our harrow disc blade size chart and the harrow discs page.

Common Buying Mistakes

• Buying the widest 3 point disc harrow the tractor can pull on paper, then finding it cannot lift it.
• Choosing a light disc harrow with 460 mm discs for heavy clay and hard stubble.
• Forgetting spare discs and bearings for the first season.

Why Buy Direct from the Factory

Shenghang makes harrows, discs, ploughs and tractors in our own factory in China. You get factory-direct supply, SH labelling or OEM branding for dealers, export packing and shipping by sea, rail or air.

Related guide: Rotary Tiller vs Disc Harrow: 6 Key Differences and Which to Buy

Related guide: Light disc harrow guide: sizes for 12–55 HP and how to adjust it

FAQ

What size disc harrow do I need for a 40 hp tractor?

A 1SH-L2.0 light harrow (2.0 m) or a 1SH-M1.5 medium harrow (1.5 m) for heavier soil.

Is a 3 point disc harrow good for clay soil?

Yes, if you choose the medium series with 560 mm discs and a width that suits your tractor.

What is the best disc harrow for a small tractor of 20 hp?

The 1SH-L1.5 with 16 discs and 1.5 m working width suits 20–25 hp.

Light disc harrow or rotary tiller for a small farm?

A harrow is faster after ploughing and needs no PTO. A rotary tiller makes a finer seedbed in one pass but uses more power.

Get a Quote

Send the model, quantity, your tractor horsepower and destination port on WhatsApp +86 133 8469 2372, or see all models on the harrows page. Shipping details are in our export guide.