Screen Selection 101: Understanding Round vs. Slotted Holes

If you look at a set of seed cleaning screens for the first time, the variety of shapes can be a bit overwhelming. You’ll see perfect circles and long, narrow slots. While they might look like just a design choice, these shapes are actually precision tools.
Choosing between round holes and slotted holes is the difference between a "clean" sample and a "perfect" one. Today, we’re breaking down the science of hole shapes so you can dial in your 150HD or 300HD for any crop.

1. Round Hole Screens: Sizing by Width
Round hole screens are the most common "top screens" (scalpers). They work by measuring the width of the seed. If a seed is wider than the circle, it stays on top. If it’s narrower, it drops through.

• Best For: Round seeds like soybeans, corn, and peas.
• The Scalping Job: A round hole is excellent at catching long "trash" like straw, stems, and pods. Because the hole is a circle, a long piece of straw would have to stand perfectly on end to fall through—which rarely happens.

2. Slotted Hole Screens: Sizing by Thickness
Slotted screens (also called oblong or rectangular screens) measure the thickness of a seed. These are essential when your crop isn't a perfect circle.

• Best For: Elongated seeds like wheat, oats, and barley.
• The "Split" Remover: For soybean growers, a slotted bottom screen is a lifesaver. It allows "splits" (broken beans) to fall through because they are thinner than a whole bean, even though they might be just as wide.

3. Which One Goes Where?
In a standard two-screen setup like the Farmstead 150HD or 300HD, the most common configuration is:

• Top Screen: Round Hole (to scalp off large trash).
• Bottom Screen: Slotted Hole (to sift out thin weed seeds and broken kernels).

However, if you are cleaning elongated grains like oats, you might use a slotted screen on the top and the bottom to ensure you are grading by the thickness of the grain rather than the width.

4. Why We Use Precision Steel
At Farmstead Products, we don't settle for "close enough." Our screens are punched from heavy-duty American steel to ensure that a 12/64" hole is exactly that—all the way across the deck. When you are fighting for a "Certified Organic" premium or trying to save the best seed for next year's planting, that precision is what puts money back in your pocket.

Ready to Master Your Screen Setup?
The right screen turns your machine into a surgical tool for your harvest.

• Talk to the Pros: Not sure if you need a round or a slot for your specific weed problem? Call the shop at 320-384-0003. We’re a family business, and we’ve seen it all.

Happy Farming!
– The Farmstead Products Family