The concave combine harvester is one of the most critical wear parts in the threshing system of a combine harvester. As a core component under the category of Threshing Parts / Threshing System Parts, the concave works together with the threshing drum or threshing rotor to separate grain from the crop. Whether you are harvesting wheat, rice, corn, or soybeans, a high-quality concave directly affects threshing efficiency, grain quality, and overall harvesting performance. Maikeyier specializes in the production and supply of aftermarket combine harvester concaves, with products meeting OEM specifications and offering competitive wholesale pricing.
What Does a Concave Combine Harvester Do?
A concave combine harvester is an arc-shaped, bar-type metal sieve plate installed below or around the threshing drum or threshing rotor of a combine harvester. The concave’s design – including bar spacing, opening size, and curvature – is carefully engineered to meet the specific needs of different crops and harvester models. Its primary function is to work with the rotating drum or rotor to thresh the crop – separating grain from the ears, stalks, and chaff.
Crop material → Threshing drum/rotor ↔ Concave → Grain and straw separation
Working Principle
- Impact: The rotating drum rasp bars strike the crop, breaking the bond between grain and stalk.
- Friction: The crop rubs between the drum surface and the concave bars, further loosening the grain.
- Compression: The gradually narrowing clearance between the drum and the concave compresses the crop, forcing grain to detach.
- After separation, smaller particles pass through the concave openings onto the grain pan below, while larger straw and chaff continue along the threshing path for further processing.
Workflow of Concave Combine Harvester
- Crop feeding: Crop is fed into the threshing chamber by the feeder house, where the threshing drum or rotor is rotating at high speed.
- Threshing action: As the crop passes through the clearance between the drum and the concave, it undergoes repeated impact, friction, and compression. The concave’s bars and openings are designed to maximize grain detachment while minimizing grain damage.
- Grain separation: Detached grain falls through the concave openings onto the grain pan, while the remaining straw continues through the threshing system.
- Adjustable clearance: The clearance between the drum/rotor and the concave (threshing clearance) can be adjusted for different crop types and operating conditions. This adjustability is essential for optimizing threshing performance.
Concave Combine Harvester for Sale
Maikeyier supplies a wide range of aftermarket combine harvester concaves in various specifications, compatible with major harvester brands. You can choose different concave solutions based on your application scenario, budget, and market needs. Our team is always ready to assist you.
Compatible Brands
We produce and supply compatible concaves for multiple combine harvester brands. Each concave is manufactured to OEM specifications for the corresponding harvester model, ensuring installation fit and operational performance.
Kubota combine harvester concaves (DC series, etc.)
Yanmar combine harvester concaves (AW series, etc.)
Lovol combine harvester concaves (Lovol RG, GE, GK series, etc.)
World combine harvester concaves (World series harvesters)
Materials
The material of the concave directly determines its durability and service life. The concave must continuously withstand impact and friction from grain, straw, and the threshing drum. Higher-grade materials and heat treatment processes naturally increase product life – and price. The principle is simple: better material properties mean higher raw material costs and higher product prices, but also better long-term cost-performance.
| Material | Characteristics | Application Scenario |
| Carbon steel | Good strength, cost-effective | Conventional harvesting under standard conditions |
| Alloy steel | Enhanced toughness and wear resistance | Medium to heavy-load operating conditions |
| High-strength steel | Excellent strength-to-weight ratio | Large-feed harvesters, harsh conditions |
| Wear-resistant steel | Superior wear resistance, long service life | Heavy-duty, long-duration continuous harvesting |
Structural Design
Bar spacing: The distance between adjacent bars. Smaller spacing retains more straw but may reduce grain passage; larger spacing allows faster grain separation but may allow unthreshed heads to pass through.
- Wire/bar diameter: Thicker wire provides higher durability but may reduce opening area.
- Opening size: Determines the size of material that can pass through. Must be optimized for the target crop’s grain size.
- Curvature: Must match the drum/rotor radius to maintain a consistent threshing clearance.
- Number of bars: More bars provide greater threshing area but also more restriction to material flow.
- Concave angle: Affects the feed and discharge angle of the crop material.
- More complex structures and higher dimensional accuracy typically increase manufacturing cost – which is directly reflected in the product price.
Surface Treatments
| Treatment | Description |
| Painting | Basic corrosion protection; economical choice for dry environments |
| Powder coating | Durable, uniform coating; good resistance to chipping and corrosion |
| Galvanizing | Excellent rust protection; suitable for humid or coastal environments |
| Electrophoresis | Superior uniform corrosion protection; high-end surface treatment process |
Concave vs. Ordinary Sieve Comparison
Although both the concave and the sieve play a “screening” role in a combine harvester, they are located at different stages of the harvesting process and have different primary functions:
| Component | Primary Function | Installation Position |
| Concave | Threshing – separating grain from ears and stalks | Below/around the threshing drum or rotor |
| Sieve | Cleaning – removing chaff and fine impurities from grain | Inside the cleaning chamber, after threshing |
| Threshing drum | High-speed impact and threshing of crop | Above the concave |
| Rotor | Axial-flow threshing and separation | Inside the rotor housing, surrounded by the concave |
Combine Harvester Concave Supplier
Maikeyier is an enterprise engaged in the production and supply of aftermarket combine harvester concaves and agricultural wear parts. We provide reliable product quality, competitive wholesale pricing, and one-stop harvester parts supply services to global dealers, distributors, and repair service providers.
Advantages
- Manufactured to OEM specifications: All concaves are produced to OEM dimensions, materials, and performance specifications, ensuring direct installation fit and reliable operation.
- High-quality materials: We use high-grade carbon steel, alloy steel, and wear-resistant steel to ensure long service life even under demanding harvesting conditions.
- Comprehensive brand coverage: We supply compatible concaves for major harvester brands including Yanmar, Lovol, World, Kubota, and more.
- Competitive wholesale pricing: Factory-direct supply eliminates middleman margins, offering you the best bulk purchase prices.
- Multiple surface treatment options: Painting, powder coating, galvanizing, and electrophoresis are available to meet different environmental and export requirements.
- Export-grade packaging: Rust prevention and sea-worthy packaging ensure safe delivery for international shipments.
- One-stop supply: In addition to concaves, we also supply a full range of combine harvester threshing parts, including rasp bars, drum bars, separating bars, and more.
Quality Assurance
- Every concave undergoes strict quality inspection before shipment, including:
- Dimensional inspection to ensure compliance with OEM specifications
- Material verification and hardness testing
- Surface treatment quality inspection
- Packaging inspection for export orders
Ordering Process
- Inquiry: Contact us with your harvester brand, model, and part number.
- Quotation: We provide a detailed quotation with specifications, material, and pricing information.
- Sample (optional): Sample orders are available for product quality verification.
- Production: Production begins after order confirmation, with quality control at every stage.
- Shipping: Products are rust-protected, packaged, and shipped to your designated destination.
FAQ – Concave Combine Harvester
Too small: Increased grain breakage, more crop damage, reduced grain quality.
Too large: Insufficient threshing, unthreshed heads pass through, increased grain loss.
Therefore, the concave’s curvature must precisely match the drum/rotor radius, and the adjustable clearance mechanism allows operators to fine-tune threshing intensity for different crop types, moisture levels, and harvesting conditions to achieve optimal results.
Looking for high-quality, competitively priced combine harvester threshing concaves? Maikeyier is your trusted one-stop agricultural wear parts supplier.Contact us today to discuss your needs, request a quotation, or place an order. Our team is ready to help you find the right concave product for your harvester.
