How to identify good or bad quality prong buckle

Buttons among the hardest button should be deducted Ipomoea, Ipomoea same deduction, how to identify Ipomoea buckle quality good or bad, I think I should be judged from the following aspects: (1) visual inspection, to see whether the fine workmanship, whether there is at the cutting edge burr, if the volume mouth wrinkled, smooth surface, consistent with long claws, eight flowering is uniform. (2) destructive test, claws and button beads, claws and eight were hit on the cloth, were tested with the dynamometer claw beads and buttons, and eight claw opened efforts, the international standard is usually 90 Newton (9 kg), adhere to 10 seconds will not pull out qualified; (3) engaging force test, eight buttons and beads constantly engaging, see if there is the phenomenon of smaller intensity, poor quality of Ipomoea buckle, after engaging dozens of times or a hundred times, there was no strength, and now, the international best Ipomoea buckle buckle force of about 1000 times the number of domestic generally about 500 times.

Million to pay the company is focused on development and production of Ipomoea buckle manufacturers, the million pairs developed new prong buckle, destroyed 15 kg or more, the deduction could force up to 1000 times without change. Target million to pay is to do the best prong buckle, focused, professiona