Cutting hair with clippers isn't supposed to inflict pain, just in case you were unsure. If there's more "ouch" in your hair cuts than in an ultimate fighting competition, something's gone seriously wrong. There are a few reasons that you might be pulling, instead of cutting, the hair. In some cases, more than one of these reasons may be the culprit.
If you're doing more pulling than cutting, there's a good chance the blades of your hair clippers have become dull. Just as with a knife or scissors, clipper blades dull with repeated use. If your blades are clean and free of clogged hair, but still don't seem to be cutting as well as they once did, it's probably time for new blades. It's a pretty easy task to change them. Just unscrew the blade head from the clippers and replace them with a brand-new sharp set. Don't forget to oil the new blades before you use them for the first time.
Insufficiently Oiled Blades
As with any machine, a well-oiled set of clippers works better and more efficiently. Because the blade of your hair clipper is a moving object (it moves fast, but it is moving) it needs lubrication, or it begins to seize up. When the blades seize up, hair in the blades gets pulled instead of cut. To oil your clipper blades, place two or three small drops of clipper oil on the blade while the clippers are turned off. Turn the clippers on and let them run for three or four seconds to distribute and lubricate all of the blade. Turn the clippers off and dab off any excess oil on the blade face. Your clippers are now oiled and ready for action.
Wet hair is notorious for clumping and clogging up the blades of hair clippers. When this happens, there will be much more pulling than cutting going on. The fix for this dilemma is simple -- always clipper hair when it's dry. Dry hair doesn't clump and fall away from the blade once it's cut, unlike wet hair, which clings to the blades and messes up everything. Not to mention that it's bad for the clippers, as the moisture can seep in and damage the internal workings.
Too Much at Hair at Once
Another common reason that your clippers pull hair may be that you're pushing the blades through too much hair at once. This often happens when you are using clipper guards and are trying to plow through the hair too quickly. To avoid this clippering no-no, make swipes with the clippers that are 1 to 2 inches long, and go slowly. When you move over to the next section, position the guard so it's half on the previously cut hair, and half on the longer, uncut hair. This gives the blades less to cut at once and cuts down on the pulling, big time.