Harrow Disc Quality Checklist: 7 Checks Before You Import Disc Blades

Harrow disc quality is hard to judge from a photo. Two offers may show the same size and price, but one batch lasts twice as long in the field. If you import harrow discs for a dealer network, a simple checklist protects your reputation. Here are the seven checks we use and recommend before any disc leaves the factory.

Harrow Disc Quality Check 1: Steel Grade

Ask the supplier to state the steel in writing: 65Mn spring steel or 30MnB5 boron steel. Boron steel is the better choice for heavy harrows and abrasive or stony soil; 65Mn is economical for light and medium harrows. Read more in our harrow disc heat treatment guide.

Check 2: Harrow Disc Hardness Test

Hardness shows whether heat treatment was done correctly. Our target is HRC 38–44 after quenching and tempering, and we check hardness on every batch. Ask for the hardness test results for your order, not just a general certificate.

Check 3: Dimensions

• Diameter (12–36 inches in our range).
• Thickness at the center (3–12 mm).
• Center hole size and type, and bolt pattern if any.
• Concavity (dish depth).

Measure several discs from different bundles. Our center hole guide explains how to measure.

Check 4: Edge and Notches

For notched discs, the notches should be evenly spaced and clean, with no cracks at the corners. For plain discs, the edge should be even all the way round. Uneven notches make the gang vibrate and wear bearings.

Check 5: Shape and Flatness

Lay discs on a flat floor. A good disc sits evenly, and discs in the same batch have the same dish depth. Warped discs run rough on the gang.

Check 6: Paint or Oil Protection

Discs should be painted or oiled against rust for sea freight. Check that paint covers the whole surface without bare patches, especially around the center hole.

Check 7: Packing and Marking

Discs are stacked and wrapped, then packed on pallets, in steel crates or wooden cases. Each bundle should be marked with size and quantity. SH marking or your own OEM brand can be applied. For mixed-size containers, see our harrow discs wholesale guide.

Why Harrow Disc Quality Varies Between Suppliers

Most of the cost of a disc is steel, so the easiest way to cut price is to use cheaper steel, thinner plate or a shorter heat-treatment cycle. None of these is visible after painting. That is why a disc blade inspection should look beyond appearance: steel grade, hardness, thickness and shape tell you far more than colour. A good harrow disc quality check takes less than an hour per batch and protects a dealer from complaints that cost much more than the goods. If you import harrow discs regularly, keep a simple record of each batch – size, grade, hardness and field feedback – so you can see which supplier and grade gives the best life in your market.

Choosing a Disc Blade Supplier in China

• Prefer a manufacturer that controls heat treatment in its own factory.
• Ask for hardness data for each batch.
• Start with a mixed trial order before a full container.
• Check that bearings and spools can be supplied with the discs.

Quality spare parts help farmers keep machines working, part of the FAO’s work on sustainable agricultural mechanization.

Related: see our full range of disc harrows – light, medium, heavy hydraulic and folding models for 12–300 HP tractors.

FAQ

How do I check harrow disc hardness myself?

A portable hardness tester can be used on a sample disc. You can also ask for our batch hardness test results.

Can I import harrow discs in mixed sizes?

Yes. Several sizes and grades can be combined in one shipment.

Are you a disc blade supplier in China or a factory?

We are the manufacturer and ship direct from our factory.

Can you put my brand on the discs?

Yes. SH marking or OEM marking is available.

Get a Quote

Send sizes, steel grade, edge type, center hole, quantities and destination port on WhatsApp +86 133 8469 2372. See the full range on the harrow discs page and shipping on our export page.