The authoritative public forum
  for Metal Finishing since 1989
-----

high resistance & black finish on steel bolts

Are there any alternative finish replacing Dacromet PB153 or Zn-Iron w/ black chromate? We need to finish bolts(plain carbon steel) of 6-8 mm diameter and 3/4 to 2 inch long. The finish should bear black color and withstand 600 hr to red rust. We tried PB153, but ran into many problems. We are not sure if Zn-Fe w/ black chromate could be as well controlled as plain Zn plating(our current process) and applicable to bolts. I would appreciate your reply.

Francis H. Hahn
- Daejeon, South Korea
2000

---

Dear Fransic, you contact to S Y Noh, who is in inchon city.the company name is DAE YOUNG CH.CO.They are making a hi-tech fluoropolymer based coating materials for application in corrosion protection for metals. PTFE like fluoropolymers are solving your problem.this coating withstand in salt spray test up to 2000hrs.and coating thickness is possible 5 micron to 200 micron.this is a worldwide suitable and proved process in hitech coating field.i think mr.Noh is a cooperative person and giving to fully help.Good Luck.

Kalyan Dhakane
Mumbai, India
2000