Common phenomenon and inspection of self-tapping screws


In addition to the torque effect of the self-tapping sc […]

In addition to the torque effect of the self-tapping screw thread, it is also subjected to the compressive stress from the self-tapping thread on the BOSS column. Self-tapping screws have their own anti-loose properties, and their main torque is used to overcome the thread forming resistance and friction, and there is almost no pre-pressure.

A.Screw skew

1.The electric batch is not vertical when it is dropped

2.The head is shaken, causing the screw to skew

3.being locked face level

a.Electric batch vertical

b.Will be placed on the locking surface level

c.The batch head shakes beyond the allowable range, repairs the electric batch

B.Nut flowering

1.The bit is worn or does not match the screw

2.The batch head is not installed, and there is shaking.

a.Replace the batch head, nut and flower

b.Adjust the batch head to install or repair the electric batch

There are three methods for self-tapping screws:

1.Functional inspection: Check whether the fastening parts are loose, whether the product gap is uniform, whether there is virtual position, deformation, scars and depressions.

2.Appearance inspection: Whether the screw is tilted, whether the screw head is in close contact, and whether the screw head has poor puncturing.

3.Reliability verification: Self-tapping screws cannot be tested with loose torque. Only torque-adjustable hand batches can be used. Check whether the self-tapping screws have a slip wire or have been tightened under tightening torque.