Mechanical properties: screw on the universal material test instrument method and screw itself is too thick cut off the test sheet and then do the experiment method. Simple test methods include the determination of screw hardness. However, because the screw head and screw tip of the cold-pressed product are hardened after processing, the shaft must be cut off and its section measured.
The inspection of self-tapping screws is: the test plate that meets the specified hardness, plate thickness and inner diameter is installed with screws, and the torque on the protruding part of the screws on the opposite side is measured. Clamp the tip of the screw to measure the torque until the screw is cut. Self-tapping screws do not need to consider the other hole position, so it is widely used. When the corresponding steel plate is thin, it is repaired on the plate to increase the actual plate thickness. The selection of the aperture relative to the lower one is very delicate in terms of performance. Used for synthetic resin pitch, tooth Angle, hill shape change after use.
