Don't let a worn sickle section cost you yield, downtime, or a broken knife drive. Cutting sections are one of the highest-wear components on any hay mower or combine header — and choosing the right replacement makes the difference between a clean, efficient cut and ragged crop loss. Here's everything you need to know about selecting and replacing AgSmart sickle sections.
What Are Sickle Sections and Why Do They Matter?
Sickle sections are the individual serrated or smooth-edged blades that bolt onto the sickle bar and do the actual cutting work. As the sickle bar reciprocates rapidly, each section shears crop against a stationary counter-knife (guard). When sections dull, chip, or crack, the result is:
- Ragged, uneven cuts that stress plant stems and reduce regrowth in hay applications
- Increased knife drive load, leading to premature pitman arm, wobble box, or drive belt wear
- Crop pushing and bunching instead of clean shearing, especially in heavy or tough-stemmed crops
- Missed grain at the header in small grains like wheat, barley, and oats
Replacing sections at the right interval — not just when they fail — is the most cost-effective maintenance habit you can build into your harvest season.
1. Selecting the Right AgSmart Section for Your Application
Not all sickle sections are created equal. AgSmart offers several section profiles designed for specific crop types and cutting conditions.
- Standard Serrated Sections: The workhorse choice for most small grain and hay applications. The serrated edge grips and shears cleanly through dry, upright crop. Best for wheat, oats, barley, and dry alfalfa.
- Smooth-Edge Sections: Preferred for green, tough-stemmed crops like soybeans or wet hay. The smooth edge slices rather than grabs, reducing wrapping and plugging in high-moisture conditions.
- Hi-Lift Sections: Feature an upward-angled profile that lifts lodged or down crop into the cutting zone before shearing. Ideal for storm-damaged fields or heavily lodged small grains.
- Coated/Hardened Sections: AgSmart's hardened sections use a specialized heat treatment or coating process to extend wear life significantly in abrasive, sandy, or rocky soil conditions where sections dull rapidly.
Key fit consideration: Always match the section to your sickle bar's bolt pattern (typically 1-1/2" or 3" spacing) and confirm compatibility with your specific header make and model before ordering in bulk.
2. Reading Wear — When to Replace
Visual inspection before and during the season is your first line of defense. Replace sections when you observe any of the following:
- Chipped or missing teeth on serrated sections — even one missing tooth creates a dead zone that pushes rather than cuts
- Rounded or polished edges — a shiny, smooth bevel on a serrated section means the hardened edge is gone
- Cracks at the bolt holes — stress fractures here mean imminent breakage and potential damage to the sickle bar itself
- Bent or warped sections — caused by rock strikes; a bent section will contact the guard unevenly and accelerate guard wear
- Excessive crop pushing in the field — if you're seeing uncut stems or the header is working harder than usual, worn sections are often the culprit before any mechanical issue
Pro tip: Replace sections in sets across the full sickle bar rather than spot-replacing individual sections. Mismatched wear levels create uneven cutting load and accelerate wear on the newer sections.
3. Tools and Prep Before You Start
Replacing sickle sections is a straightforward job with the right setup. Gather the following before you begin:
- Sickle section riveter or bolt kit (AgSmart sections are available in both riveted and bolted configurations)
- Sickle bar clamp or vise to hold the bar steady during installation
- Punch and hammer for driving out old rivets if applicable
- Torque wrench for bolted sections — over-torquing cracks sections at the bolt hole
- Wire brush and penetrating oil to free corroded fasteners on older bars
- Safety gloves — sickle sections are razor-sharp even when worn
4. Step-by-Step Replacement Process
Step 1 — Disengage and lock out the header.
Lower the header to the ground, disengage the knife drive, and follow your machine's lockout/tagout procedure. Never work on a sickle bar without confirming the drive is fully disengaged.
Step 2 — Position the sickle bar for access.
Cycle the sickle bar by hand (with the machine off) to position the worn sections in an accessible location. Many technicians work from the front of the header with the header lowered flat.
Step 3 — Remove the worn section.
For bolted sections, remove the nut and bolt. For riveted sections, use a punch to drive out the rivet from the back side of the bar. Inspect the sickle bar at each location for cracks, burrs, or deformation before installing the new section.
Step 4 — Install the new AgSmart section.
Align the new section with the bolt holes in the sickle bar. For bolted installations, hand-thread the fastener first, then torque to spec (typically 8–12 ft-lbs — confirm with your header manual). For riveted installations, use a proper sickle riveter to set the rivet flush — a proud rivet will contact the guard and cause immediate damage.
Step 5 — Check guard alignment.
After replacing sections, manually cycle the sickle bar and verify each new section passes cleanly through its corresponding guard with minimal side play. Bent or misaligned guards should be replaced or straightened at the same time.
Step 6 — Inspect the knife drive components.
A full section replacement is the ideal time to inspect the pitman arm, wobble box oil level, and drive belt for wear. Catching these now prevents a mid-season breakdown.
5. Extending Section Life Between Replacements
A few operational habits can meaningfully extend the service life of your AgSmart sections:
- Maintain proper cutting height — running too low increases soil and rock contact, the fastest way to dull or chip sections
- Keep guards tight and properly aligned — a loose or bent guard creates uneven shear load on the section edge
- Lubricate the sickle bar regularly — a dry bar runs hotter and accelerates wear at the section-to-guard interface
- Carry spare sections in the cab — a mid-field section failure doesn't have to end your day if you have replacements and a basic tool kit on the machine
Shop AgSmart Cutting Sections at Quality Farm Supply
Whether you're running a disc mower, a draper header, or a sickle-equipped combine, Quality Farm Supply stocks AgSmart cutting sections to fit the most popular JD, Case IH, New Holland, and MacDon platforms. Order online with confidence — our team knows ag equipment and can help you confirm the right fit before you buy.
Have a question about sickle section selection for your specific header? Contact our parts team — we're here to help you cut clean and harvest more.
