A cutter-binder, also known as a grain binder or simply a binder, is an agricultural machine used in the process of harvesting and bundling cereal crops, such as wheat, oats, barley, and rye. It was commonly used in farming before the widespread adoption of combine harvesters. Here’s how a cutter-binder typically works:

1. Cutting: The cutter-binder is towed by a tractor or horse-drawn. It is equipped with a cutting mechanism, often a sickle bar, which is positioned at the front of the machine. As the machine moves forward through the field, the sickle bar cuts the standing cereal crops at their base, leaving the cut stalks lying flat on the ground.
2. Gathering and Binding: After cutting, the machine has a gathering mechanism that collects the cut crop into a bundle or sheaf. These bundles are typically a fixed size, and the machine has a binding mechanism that ties the cut stalks together with twine or wire to form a compact bundle.
3. Ejection: Once the bundle is bound, the cutter-binder ejects it onto the ground, often in a neat row or pattern, where it can be left in the field to dry and later collected for further processing or storage.
4. Transport: In some cases, the bundles may be loaded onto a wagon or cart directly behind the cutter-binder for transportation to a storage area.