Special Flange Nut

The grade of this special Haixin® flange nut is class 10 per ISO898-2. The raw material for this special flange nut should be free from harmful internal and external defects. Our factory always uses premium 35CrMoA or 42CrMoAfor this collar nut.These materials have a high standard of surface quality and mechanical property. So the quality of the special flange nut is well ensured from the original raw material.During past years, Ningbo Haixin Hardware Co.,Ltd has invested a lot of manpower and financial resources and purchased lots of advanced automatic machining and producing machines to improve and grade our product quality. And also because of this, our factory can survive the market and competition.

For this special Haixin® flange nut, approximately 90% martensite in the core of the nut must be ensured, so the steel have sufficient harden ability and the products should be well heat treatment. And decarburization of the special flange nut thread shall be measured in analogy to external  threads as given in EN ISO898-1. Our factory will strictly carry out every test of the collar nut. Testing including dimensions, gauges, decarburization, hardness, proofload, run out, marks and finish are carried out on every batch.