Bushel Plus O-Grate MAD concaves aim to combat grain loss

Outdated or underperforming concaves are a major source of profit loss during harvest. When concaves can’t keep up with today’s high-capacity combines, farmers risk unthreshed grain, cracked kernels, and restricted machine performance caused by plugging or reduced rotor efficiency.

Marcel Kringe, founder and CEO of Bushel Plus and an expert in harvest optimization, says many farmers underestimate the impact of outdated concaves.

“The concave is the heart of the threshing system,” Kringe said. “Yet too many machines still run with concave designs that haven’t changed in decades. Every field with old components like this risks losing grain.”

Next-Gen concaves for every crop

Engineering advancements in concave design are transforming harvesting efficiency

 “Today’s concave technology far outperforms the standard designs and combine setups, allowing farmers to optimize threshing for every crop that they grow,” he says. “This reduces losses and improves grain quality.”

A standout in advanced concave innovation is the Bushel Plus O-Grate MAD Concave, which replaces traditional round-bar concaves with a precision-engineered design for corn, soybeans, sorghum, sunflowers, and other pulse crops.

The O-Grate incorporates two key design innovations new to the industry:

  1. O-shaped holes for controlled and consistent threshing
  2. Rounded staircase-style threshing bars for gentle grain separation

“These innovative design features solve common problems with standard concaves,” Kringe said. “They prevent unthreshed grain, reduce kernel damage, and maintain consistent performance even in challenging conditions.”

(Courtesy photo.)

How the O-Grate works

The O-shaped holes allow grain to separate efficiently while keeping larger crop material in the rotor without overloading the sieves. This controlled flow prevents plugging and ensures more grain reaches the bin. Meanwhile, the staircase-style bars create a tumbling motion rather than harsh impact, protecting grain quality and storage value.

“We designed the O-Grate to push the boundaries of what farmers can expect from their combines,” Kringe said. “By increasing throughput and capacity, improving sample quality, and reducing grain loss, we’re helping growers harvest more efficiently and protect their bottom line.”

Modular design for quick crop swaps

Bushel Plus’ concave system, in general, is a modular split-frame design, which allows quick insert swaps between crops or conditions.

Unlike traditional concaves that are heavy and time-consuming to change, this precision-threshing design enables a single operator to swap lighter inserts within the frames from a cereals or small grains concave to the O-Grates for corn or soybeans in just 10 to 15 minutes, without the need to re-level the concaves—reducing downtime and improving safety.

For the 2025 season, O-Grate MAD Concaves are available to U.S. farmers running: Case IH Flagship and Midrange; John Deere STS, S series, and X9; Fendt Ideal; and New Holland CR 22-inch combine models.

For more information, see a dealer or visit bushelplus.com