hubertsprings

Take the spring by hand and place it in the cavity inside the knife as in the drawing. Place the other end of the spring in the choil or notch in the blade , and by closing the blade, lever the spring as deeply into the cavity as possible. Sometimes it is necessary to use a punch or a nail to lever against the blade tang to push the spring all the way in. This is especially true with the 14cm knives and is almost always necessary to take this additional step to get the spring fully in place. If the knife doesn't open properly , this is almost always the reason, so try to lever it deeper into the cavity. Take care not to overbend the spring , as it could break.

Here are the shapes and sizes of the 4 most common knife sizes. These are pretty close to actual size and shape BEFORE they are installed. (The 12cm knife spring is approx. 7.5 cm.) After they are installed they will usually flatten out a little bit from the first closing.

If a spring breaks, you do not have to take the knife apart to replace it. I first soak some WD40 or any penetrating oil into the spring cavity. This will help lubricate and dissolve any rust that may have accumulated. I use a 1/8" round hobbyist file that has about 1/2" that broke off the end. This hard material has a jagged end that bites into the spring material fairly well. Any type of punch or hard metal that fits between the liners will do. I first hit it straight down with the hammer to make a ding in the broken part of the spring. Then by holding it at an angle I keep tapping until the broken part of the spring comes out. You will want to have the knife up against something solid so it doesn't walk away from you. Replace with a new spring as per the above instructions.