Now many of the taps on the market a lot, because the use of different materials, with the specifications of the price is also a lot of difference, so that buyers like smoke and mirrors, I do not know what to buy, the following teach you a few simple ways:

    At the time of purchase (except for no test equipment, no trough taps) can be a simple test (M6 example):

    1: see the taper tapered front-end thread grinding mill (chamfer) is uniform, cutting slot blade whether there is a quick mouth, good was positive 7 font, bad inverted 7 words or U-shaped (exit wire attack will cause twice Cutting, easy to break and affect the accuracy of the thread);

    2: detection of heat treatment situation: pull wire cone to the air was parabolic (5 meters) flat down whether the break, broken description of brittle;

    3: knock the taps to see it fracture is slanting, fracture of the molecular particles (microstructure 10.5 #) detail, indicating heat treatment and material is good, flat or oblique short, molecular particles (microstructure) Rough is not good.

    The quality of the tap is mainly depends on its original material, heat treatment, groove type, precision, equipment, speed and processing material, hardness, the quality of the staff have a relationship! When using the tap, the original material of the tap, heat treatment, groove to pay special attention to, for different processing holes, it is recommended to choose different types of tap!