On JD and CIH P-500/NH P-2080/85 single disc drills (with 18″ blades), blades should be replaced at 17 3/8″ diameter or sooner. At Exapta, we encourage blade replacement sooner rather than later, because at this point over half the bevel is gone and very dull. The bevel is 3/4″ new. Once 5/8″ wears off, you are at the maximum dullness. Not only will you experience more trouble with hair-pinning, but the blades will struggle to cut the soil. Continuing to run worn out blades will escalate seed boot wear. Because the boot is wider than the furrow being cut, it is very difficult to push the boot into the soil. Generally, the lower edge of the boot should be approximately at the soil surface. It doesn’t take much figuring to determine whether blades or seed boots are more expensive to keep up to spec in the long run!
Remember: the last acre planted is just as important as the first! Replace your blades often enough to stay well above 17 3/8″ throughout the entire season. You’ll find greater savings in the long run by replacing blades more often, taking into account better performance of the whole opener. A brand new 18″ blade will require less downforce on the opener, resulting in a clean cut furrow and less hair-pinning, all while keeping the seed boot at soil surface to prevent premature wear.
Quick TIP: To measure blades without removing the blade, measure from the edge of the hub to the blade edge. Replace if less than 5 7/8″. And, when installing new blades the bevel should be towards the seed boot.
In no-till, an up-to-par blade is essential for making efficient use of down-pressure and forming a clean furrow, so the seed can reach the bottom, for good seed-to-soil contact. Exapta carries excellent long-lasting blades with the Forges De Niaux. Our farmer testing has proven the Forges de Niaux gives the best life compared to OEM. We also have Ingersoll blades at the close out price of $28 with limited inventory. Keep those blades up-to-spec and a lot of seeding problems are eliminated.