What is the acceptance method of special screws
The quality of the product must not be strictly produced in accordance with the corresponding standards. What are the acceptance standards for special screws?
First of all, the special screw is also the evolution of the national standard screw. It is also necessary to determine the specific test items according to the national standard screw surface defect standard. Please refer to the corresponding national standards in this regard. Pick away before the inspection.
Secondly, according to the design drawings requirements, the size and material of the special screws are inspected. This should be paid to the test of the material, and the raw material manufacturer must provide the material certificate report. Second, high -end products must require SGS material certification and send relevant laboratory to perform material composition analysis to confirm whether the content of the ingredients meet the requirements of the drawing material.
The functional requires non -destructive examinations. If non -destructive inspections are performed on non -standard screws, if you find that there are quenching cracks on any part, the inspection of the sideline, and the below of its wrinkles, and whether the coating meets ROSH environmental protection requirements.
Then there is a destructive test, such as the special screw hardness level for the corresponding hardness impact test; internal hardness, mechanical properties, torque testing, etc. This will damage the special screws, but the screw factory with strong quality concepts must be Do test items.
DIA：#6-3.5 #8-4.2 #10-4.8 #12-5.5 #14-6.3
HEAD：bugle head,Hex washer head,flat head,Pan Head, wafer head,pan framing head
Surface：black phosphate,zinc plated,Yellow Zinc plated,Ruspert,Magni
Thread：BSD thread CSD thread