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

Can't Rusted Fasteners Be Rejected?

Ok, I have a few Million fasteners that are supposed to be Steel with Nickel Plate over Copper Flash that show rust in the Drive & Under the heads. Not every carton has bad parts, some more than others. My question is, Under What Specification can I reject these parts? I know that for Mixed & Foreign material there is a standard of so many parts per million pieces that can be allowed but what is the standard for Rusted / Corrosion Parts? I know that all orders are not 100% free from defect but shouldn't I be able to reject the entire lot of screws due to Rust & Corrosive Parts? In some cartons there are only 100 pieces out of 19,000 but in others there are well over 200 pieces bad. What should I do here?

Tony Keas
Fastener Distributor - Chicago, Illinois
2007

---

Hi,Tony, From the letter I believe you are not sure whether the parts are nickel plated over copper flash.Please be sure about this.QC(Quality control) spec.is generally defined and understood between the buyer and the supplier.Of course there are universally accepted norms which I do not think is not the discussion now. As far as plating is concerned,0% rejection is the norm and is very difficult to obtain.So depending upon the complexity of the product the buyer and the seller have an understanding about the acceptance of % reject. So sit with your customer.understand his problems.have an agreement between both. Regards, T.K. Mohan plating process supplier - Mumbai, India Of course you can reject and must accept them under whatever specification you ordered them. If you ordered with no specification, you may be out of luck. If I order a "cheese sandwich, NOS", can I send it back if made with cheddar when I wanted Swiss, or if I wanted white bread, not rye? Jeffrey Holmes, CEF Spartanburg, South Carolina Rather than using some other specification, you need to develop your own regarding the rust/corrosion. Just because a part does not arrive rusted does not mean that it has been properly finished. One way to write your requirement would be to address an existing spec i.e. ASTM and then append that for your needs. Gene Packman process supplier - Great Neck, New York To what specification(s) were these fasteners ordered? If supposedly ASTM, MIL, NAS or SAE fasteners (anything with a grade mark), melt down any crappy fasteners from a non-qualified manufacturer (don't merely sell to a scrap dealer). Read the Fastener Quality Act (FQA) and amendments thereof: http://ts.nist.gov/WeightsAndMeasures/fqaregs2.cfm. Note that there are several exemptions; notably, for fasteners < ¡ inch (although commercial liability will still apply). Ken Vlach [deceased] - Goleta, California Finishing.com honored Ken for his countless carefully researched responses. He passed away May 14, 2015. Rest in peace, Ken. Thank you for your hard work which the finishing world, and we at finishing.com, continue to benefit from.

It turns out that we cannot detect any Copper Flash that is supposed to be under the Nickel Plating. We did not order these per any specific spec. The print called out for steel material & nickel plate over copper flash. So I believe that because the x-ray machine cannot detect any copper flash, rust has formed on the steel & is coming through the nickel.

Tony Keas
- Chicago, Illinois, USA
2007

---

Whether there's copper under the nickel or not, if the plating is not done to any specification, especially as regards thickness, you may have rusty parts. Please reference an appropriate specification in your purchase order.

Jeffrey Holmes, CEF
Spartanburg, South Carolina
2007

---

2007

Hello Mr Tony Keas,


Technically speaking :
If you have specified copper before nickel, the parts are going to corrode much faster than just nickel over steel.

Your spec is wrong and is probably from the 1960's.The copper is going to accelerate corrosion.

You would have been better of specifying duplex-nickel that is a twin nickel coat that offers much much better corrosion resistance than copper - nickel.

Yes the X-ray beam cannot detect just a micron or two of copper, and gives a consolidated reading mostly erroneous
if you are trying to detect very thin copper.

Whilst on the subject in defense of the supplier/plater..

If you bought the fastener and had a specification beforehand then you were under obligation to test the fastener before accepting the material. The supplier is not obligated to be your inspector.

If you have accepted the material and there is more than reasonable time elapsed between which some of the fasteners have corroded, it is a very normal process and you cannot reject the fasteners for some of them being corroded.

Every plating spec in the world has both an upper and lower limit for plating thickness, also a fastener is ultimately subject to a thread gauge test. If this was the case then the plating thickness issues cannot be taken up as fasteners also vary in the thread gauge conditions before plating, and are plated to suit the thread gauge.

Its difficult but not impossible to test a curved surface with either X ray or otherwise, except for flat portions.

Please also note that if the fasteners have undergone a sea journey or been subject to packing and temperature variations of any kind before reaching you, please remember that the fastener was supposed to pass tests after plating, not after being packed for months, shipped, and inspected at some future date.

No one or no process in the world can ensure that the fastener will remain forever without corrosion, that's why they are plated in the first place.

Since these fasteners were in your ownership, you are obligated to segregate and sell good fasteners, as did the supplier/ plater before you. Your choice of buying from him again is a different matter altogether, but rejecting the fasteners is gross injustice.

warm regards from India,

Khozem Vahaanwala
Saify Ind

Bengaluru, Karnataka, India