What is Square-Ground Filing and How Do You Do It?
The term “square-ground filing” refers to the process of using a file to sharpen square-ground chain by hand. Square-ground filing can be much more difficult than round filing and requires different techniques. Because square-ground chain is less forgiving of errors, it is important that the corner alignment and filing angles be precise.
Learning the proper method for square-ground filing can take time. In fact, most people don’t get it right on their first try. So, don’t get discouraged if your chain doesn’t perform the way that you expect it to on the first attempt.