Vertical Tillage Blades vs. Disc Harrow Blades — What's the Difference?

John Deere tractor pulling a red disc harrow through Iowa cropland

Vertical tillage tools have taken over a big share of the residue-management market in the last 20 years. They look like fast, shallow disc harrows — and they use blades that look like disc harrow blades. But the blades are engineered differently, and they aren't always interchangeable with the older discs even when the diameter matches. Here's what actually changes between the two.

Vertical tillage vs disc harrow: the short answer

Vertical tillage runs faster, cuts shallower, and slices residue. A traditional disc harrow runs slower, cuts deeper, and rolls the top few inches of soil. Same-looking blades, different job.

  • Vertical tillage tool — 7-10 mph, 2-3" depth, thin (4-5mm) heavily-notched blades, minimal soil throw. Job: size corn stalks, warm the seedbed, prep for planting without opening the profile.
  • Traditional disc harrow — 4-6 mph, 4-6" depth, thicker (6-8mm) blades at a bigger gang angle, moves soil sideways. Job: bury residue, break up cover crops, primary or secondary tillage.

If you're deciding between the two: use a disc harrow when you need to incorporate residue into soil; use vertical tillage when you need to manage residue on the surface without disturbing what's below. The rest of this page covers blade-level differences, cross-fitment, and OEM specs.

High-speed disk vs vertical tillage — same thing?

Almost, not quite. A high-speed disk (Kuhn Excelerator, Salford Independent, Väderstad Carrier) is a specific evolution of vertical tillage that adds concavity and a slightly heavier build so the tool can run faster and move a bit of soil. Where a pure vertical tillage tool tries to leave the profile intact, a high-speed disk works ground more like a shallow disc harrow at VT speeds.

Blade-level differences: high-speed disk blades often run 22-24" (vs 20-22" on pure VT), 5-6mm (vs 4-5mm), with slightly more concavity. They wear more like a traditional disc — 800-1,200 acres — because they're doing more work per pass. If a dealer calls a machine a "high-speed disk," expect blades on the heavier end of the VT range.

For most farmers, "high-speed disk," "vertical tillage tool," and "high-speed tillage" get used interchangeably. When you're ordering blades, ignore the machine's marketing name and read the spec plate for diameter, thickness, and axle bore — that's what fits.

What "vertical tillage" means

Vertical tillage tools (Case IH True-Tandem, JD 2623/2625/2660, Krause Excelerator, Sunflower 6631, Great Plains Turbo-Till) run gangs of shallow-angled, aggressive blades at higher speeds than a traditional disc harrow — 7-10 mph vs. 4-6 mph. The goal is to slice through corn stalks and other residue, mixing it into the top 2-3 inches of soil without inverting the profile. The name "vertical" comes from the fact that the blades cut mostly straight down, not laying soil sideways like a traditional disc.

Blade differences

  • Notch depth. VT blades typically have deeper, more aggressive notches — 8 to 13 waves around the circumference on VT blades vs. 6-8 on traditional harrow blades. The waves help engage and cut residue at speed.
  • Blade thickness. VT blades are often thinner (4-5mm) than heavy tillage blades (6-8mm), because they aren't cutting deep enough to need the mass. Thin blades also flex slightly at speed, which helps residue slice.
  • Diameter. VT blades cluster tightly around 20-22". Traditional harrow blades range 22-32". You can find some VT-style blades at 24", but the big-diameter heavy blades don't exist in a true VT profile.
  • Concavity. VT blades are less concave than traditional harrow blades — flatter, more like a coulter. Less concavity means less soil-throwing and more slicing.

Can I run a disc harrow blade on a vertical tillage tool (or vice versa)?

Sometimes, if the diameter and axle match. But the results will be off from what the machine was engineered for. Running a traditional deep-concave harrow blade on a VT tool at 8 mph will throw more soil than the machine was designed to handle — you'll get bermed rows and rough finish. Running a VT blade on a traditional disc harrow at 5 mph will underperform on depth — you'll be doing a shallow pass with a machine that's designed for a deep pass.

Match the blade profile to the machine's intended use, not just the diameter.

Not sure it fits your machine? Text a photo of your old blade to 641-332-4102 — we'll cross-check the diameter, thickness, and axle-hole shape against our catalog before you order. Same-day ship on orders placed by 12pm CT.

What OEMs use on VT tools

Wear rate — VT vs traditional

VT blades typically wear faster in acres per year because they run at higher speeds and have thinner cross-sections. A traditional harrow blade might do 800-1,000 acres; a VT blade often does 600-800. But the machine covers more acres per hour, so total service life in hours can be similar or shorter.

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Frequently Asked Questions

What is the difference between vertical tillage and a disc harrow?
Vertical tillage runs faster (7-10 mph) at shallower depth (2-3 inches) to slice residue on top of the soil, using thin (4-5mm) heavily-notched blades. A traditional disc harrow runs slower (4-6 mph) at deeper depth (4-6 inches) to bury residue and mix the top few inches, using thicker (6-8mm) more-concave blades. The tools look similar but do different jobs.
Is a high-speed disk the same as vertical tillage?
A high-speed disk (Kuhn Excelerator, Salford Independent, Väderstad Carrier) is a subtype of vertical tillage that adds slightly more concavity and heavier blades (5-6mm) so it can work soil while still running at VT speeds. Pure vertical tillage tries not to disturb the soil profile; a high-speed disk works ground more like a shallow disc harrow. Terms often get used interchangeably in the field.
Are vertical tillage blades and disc harrow blades interchangeable?
Only if the diameter, axle bore, and edge type all match — and even then, the machine was engineered for a specific blade profile. A traditional deep-concave blade on a VT tool will throw more soil than expected; a VT blade on a traditional harrow will run shallower than expected. Match blade to machine.
Why are VT blades thinner than traditional harrow blades?
Because they don't need the mass. VT tools run shallower (2-3" cut) and rely on speed rather than weight to slice residue. Thinner blades also flex slightly under load, which helps them slice through stalks at high speed.
Can I sharpen or re-edge a worn VT blade?
Not recommended. VT blades are designed with a specific edge geometry (usually a symmetrical bevel) that's hard to reproduce in the field. Once the notches are worn back, retire the blade.
What is a turbo coulter?
A turbo coulter is a heavily-notched, shallow-concavity blade designed to slice through residue at high speed on a VT tool. "Turbo" is a marketing term used by Great Plains (Turbo-Till, Turbo-Max, Turbo-Chisel). The blade itself is basically an aggressive VT blade with more waves per circumference.
How fast should I run a vertical tillage tool?
Manufacturer specs vary, but 6-9 mph is the typical operating range. Below 5 mph, the blades don't generate enough tip speed to properly slice residue. Above 10 mph, you're stressing the bearings and gang bolts. Sweet spot is usually 7-8 mph.