Comment choisir des vis auto - taraudeuses ailées bon marché? Ces trois étapes peuvent vous aider à choisir des vis auto - taraudeuses ailées bon marché:

1. Measuring the outer diameter

Inferior good price and quality Self Drilling Screws With Wings are generally thin and short, measure the outer diameter, and you will find that it is obviously smaller than the good price and quality Self Drilling Screws With Wings qualified by the national standard. Some require good price and quality Self Drilling Screws With Wings with spring washers, or even without spring washers. The main function of the spring washer is to pressurize, if the spring washer is missing, the tightness of the good price and quality Self Drilling Screws With Wings will decrease.

Second, look at the appearance

Generally qualified good price and quality Self Drilling Screws With Wings need to undergo surface treatment, so the surface has high gloss, there is no blisters, and the connection parts are relatively smooth. The inferior good price and quality Self Drilling Screws With Wings has shallow threads and many burrs because of the rough processing technology, and even found that the good price and quality Self Drilling Screws With Wings have different angular widths and shallow thread grooves. Poor thread uniformity, such good price and quality Self Drilling Screws With Wings are prone to breakage.

3. Check the certificate of origin of the product

Generally, good price and quality Self Drilling Screws With Wings of qualified quality will place a certificate of conformity inside the box, and a certificate of origin will be attached.