Sourcing marine metal parts

To the editor: Tim Bittel’s report on his toggle failure (“Running backstay saves mast off Bermuda,” March/April 2009) notes he wishes he had investigated in advance how the failed toggle was made. Beyond determining whether parts are cast or forged, as a practical matter, can prospective purchasers determine with confidence how parts are made and what the metal quality is? Is it more a matter of determining by whom and where they are made?

A few years ago I took pains to purchase rigging terminals that I understood to be made in Denmark, only to discover after one of them cracked and corroded in 18 months that it had been made by an “offshore” supplier (meaning in this case, Taiwan) to which the U.S. retailer had switched its business. Given the prevalence of Asian suppliers and the widely-reported poor quality control for some metal products made there, I agree caution is called for. But absent strict industry or governmental standards and inspections, I’m not sure what boaters can or should rely on, other than a company’s general reputation.

—Roger Martin lives in Urbanna, Va. , just off the Rappahannock River. Martin cruises on Bucket, his 26-foot Westerly Chieftain that he has owned since 1979.

Contributing editor Chuck Husick responds: It is close to impossible to determine the quality of a metal part, even one as simple as a small diameter shaft a few inches long, by visual examination, or in the case of stainless steel with the added use of a magnet. Knowing the quality — strength and corrosion resistance of a more complex part, including a rigging screw, toggle or a device such as a backstay adjuster — is even more difficult. Sending the part to a laboratory for metallurgical analysis would provide some useful information, however it would not necessarily tell you if the manufacturing process preserved the strength of the material. Even good material can contain flaws.

For example, I have encountered aircraft propeller blade forgings, made by the best forging house, that contained inclusions that were not discovered until late in the manufacturing process (but well before the blades were finished). The comment about the small diameter shaft is included because one of the best manufacturers of seacocks discovered that an incorrect stainless steel alloy had been used in the manufacture of a large number of products (all of which were replaced at no cost to the user). In my opinion, the only practical way to maximize the likelihood of obtaining quality parts is to rely on the reputation of the manufacturer, and if in doubt about the origin of the part, ask pointed questions. Asian suppliers can and do produce first-rate products, however the very rapid expansion of sourcing in China has opened the door to some less than stellar suppliers at the component level and on occasion for complete products.

By Ocean Navigator