The Krause 4900 disc harrow has been in Midwest fields since the 1990s and is still the workhorse on a lot of grain operations. When the blades wear out, replacing them one at a time is a false economy — the gangs run best when the whole set is close to the same diameter. Here's how to order a full-gang blade kit for the Krause 4900 without over-ordering, under-ordering, or ending up with the wrong axle-hole shape.
What blades does a Krause 4900 use?
Most Krause 4900 configurations run 24-inch disc blades on either a 1-1/8" or 1-1/2" square axle. The exact axle size varies by production year and by whether the machine was ordered with the heavier gang option. The only reliable way to know which axle you have is to pull one bolt-on end cap and look at the shaft — square measuring 1-1/8" across the flats is the small axle, 1-1/2" is the large.
Blade thickness is typically 6mm (roughly 1/4") on the standard Krause 4900. Heavier-duty variants use 8mm blades. Match what came out.
How many blades in a full gang set?
A standard Krause 4900 with two 18-blade gangs needs 36 blades total for a full replacement. Wider machines (some 4900s were built up to 33') can run up to 52 blades across both gangs. Count the blades on your machine and add 2-4 extras — you'll want spares in the shed for the times a rock takes one out mid-season.
Notched, smooth, or mixed?
The consensus front-gang / back-gang setup for the Krause 4900 in corn-and-bean country is:
- Front gang: notched — grabs and slices corn stalks and heavy residue on the first pass.
- Back gang: smooth — finishes and levels without over-fluffing the seedbed.
Operators in heavier residue or tougher ground sometimes run notched on both gangs. Operators doing lighter secondary tillage occasionally run smooth on both. Neither is wrong — it comes down to what your specific field conditions require.
Full details in our notched vs. smooth disc blades guide.
Ordering the kit
For a standard 36-blade Krause 4900 gang kit:
- Order 18 24" notched disc harrow blades for the front gang
- Order 18 24" smooth disc harrow blades for the back gang
- Add 2-4 spares in each edge type
Ordering 20+ blades of any single size automatically triggers our 10% ag-shop discount at checkout. Free shipping kicks in at $600, and a full 36-blade set clears that threshold easily.
Full-gang replacement vs blade-by-blade
The math on this one is simple. If your front gang is at 22" diameter (from an original 24"), running it another season means those blades will finish at 20" — below the useful threshold. You'll be replacing them next winter anyway. Doing the whole gang at once means:
- All blades on the gang cut at the same depth (no uneven wear stress on the axle)
- You only pay shipping once
- You catch the bulk discount tier
- You know the setup is fresh going into spring tillage — no mid-season blade swaps
Cross-references and shop-around
Krause blades cross-reference to OEMs including Kuhn-Krause part numbers and to aftermarket blades from major suppliers. What you're paying for on an OEM catalog listing is the Krause name; aftermarket blades from Osmundson-family manufacturers meet or beat the OEM spec on heat-treat and material grade. Every blade we ship is from an authorized aftermarket source and cross-refs to the Krause OEM number where applicable.
If you're not sure whether your specific 4900 uses the small or large axle, or you're running an older Kuhn-Krause variant, text a photo of your old blade to 515-686-5575. We'll confirm the fit before you order.