I believe Wurth carries yellow zinc plated metric fasteners; perhaps others on the internet as well. A discussion started in 2011 but continuing through 2018. Yellow Zinc Plating vs. Clear Zinc. racookpe1978 (Nuclear) 17 Dec 14 04:29 Will she-who-must-be-obeyed get upset if I bring in either of my 16 oz regular hammers, or should I use the heavier 24 oz sledge hammer to squish garlic? The 2006 International Residential Code states, “ Fasteners for pressure-preservative and fire-retardant-treated wood shall be of hotdipped zinc-coated galvanized steel, stainless steel, silicon bronze or copper. Both add a layer of zinc to the outside of the product.
The thin zinc plating will quickly succumb, leaving the aluminum and steel to corrode next. So these are the basic corrosion coating and plating methods for steel. However, stainless steel is reactive with aluminum, and when a stainless steel screw is in contact with an aluminum base metal, the aluminum is likely to corrode. Galvanizing on HDG bolts will last longer. Zinc protects the steel by sacrificing itself – called a “sacrificial anode”. In general, if you have a tiny area of zinc coating and a large area of stainless steel, the zinc will be consumed fairly quickly. In our industry, stainless steel casters should be used in heavy wash down environments or where they will be exposed to cleaning agents, caustic solutions, steam, chemicals and other abrasive solutions. Meanwhile, stainless steel, an alloy that is capable of resisting corrosion. Grade 8 bolts that are not galvanized or plated with yellow zinc, however, are cheaper. The coating weights for zinc-coated fasteners shall be in accordance with ASTM A153. But stainless can also be rather 'passive', i.e., not encouraging that electrical flow. Stainless steel is an alloy of carbon steel that is, itself, resistant to corrosion. But don’t be a magpie and just pick up the shiny object – think about the use.
One-half inch (12.7mm) diameter or greater steel bolts. Black Zinc — Black zinc coatings are available as a black oxide that can actually be olive-drab in color, or as a pure black coating. That coating is eventually consumed. The second process is that scientists in the 1700s came upon the idea of coating a steel object in molten zinc to increase its ability to withstand water and subsequent corrosion. Black Oxide: Black: Ferrous metals and stainless steel: Fair: A chemical discoloration which does not add to part thickness. I was hoping to … In general, Zinc alloys are relatively inexpensive compared to stainless steel (because Zinc is cheaper than Chromium ). GLMF specializes in trivalent passivation for zinc and yellow, zinc and clear, zinc and black, zinc and olive drab, zinc nickel, stainless steel passivation, and other finishing processes to meet our customer’s specifications.
Strong stuff, sure, but prone to corrosion by its very nature. Stainless steel casters are much more expensive than zinc plated casters because of the oxidation process and materials used in the metal. We listed some of the similarities and differences here to help companies make the right choice for their product. Both aluminum and stainless steel have their own specific processes… stay tuned.