Lead Free Bronze Bushings
On January 4, 2014 the “Reduction of Lead in Drinking Water Act” became in effect. This new law mandates that any products that come in contact with drinking water must contain less than 0.25% Lead. It covers all devices at the point of use that are intended to dispense water for human consumption. This is a much stricter mandate than the current federal requirement which allows a lead content of up to 8%. This law makes it illegal to sell or install products that do not adhere to the new requirement.
While the term “lead free” still doesn’t truly mean “lead free”, the new requirements are far stricter than the previous definition. The standard will affect much of the bronze and brass products used in drinking water applications. Lead is used in the composoitions of various alloys for a number of reasons, and the removal of this element can greatly affect the alloys properties.
The Role of Lead
It’s widely known that lead promotes machinability in copper alloys. Lead acts as an internal lubricant and assists in chip break up, while at the same time not affecting the structure and properties of the copper. This is due to the fact that lead is practically insoluble in solid copper. The copper solidifies first leaving the lead to distribute throughout the copper alloy in the form of small pools, filling voids and improving machinability. Because of its role as an internal lubricant it reduces friction, and thus heat when machining. Lead allows these alloys to be machined at much higher speeds which result in shorter cycle times. In bearing materials lead acts as a solid lubricant and enhances bearing properties. As a result of these benefits many of the bronze and brass components in drinking water applications are of leaded copper alloys.
Under the new mandate these alloys will be illegal to be used. Manufacturers and suppliers now have to switch to alternative lead free copper alloys, many times losing the benefits associated with the leaded alloys. One of the most widely used bronze alloy C93200 will no longer be allowed in those applications. In order to offer our customers a solution to this dilemma we are now offering bronze bushings machined from alloy C89835 Bismuth Tin Bronze.
C89835 Bismuth Tin Bronze is a lead free C932 replacement. This is accomplished by replacing lead with Bismuth. This is possible because Bismuth, when added to a copper alloy acts identical to Lead as far as dispersing throughout the alloy and forming small pools. As a result of this similarity, C89835 Lead Free Bronze has very similar advantages in machinability and internal lubrication that are associated with C93200 Bearing Bronze. This alternative allows you to remain compliant under the new regulation while not sacrificing ease of machinability or cycle time. C89835 is also a suitable lead free replacement for C836 and C844 Bronze Alloys.
Lead Free Alloys
C89835 is not the only lead free bronze alloy that we use to manufacture lead free bronze bushings. There are a number of alloys that are either naturally lead free or designed to be alternative for other lead containing alloys. Below is a list of the lead free bronze alloys that we commonly use in the manufacture of lead free bushings, follow the alloys link for technical information on the specific alloy. Based on your applications needs there may be a great replacement to the leaded alloy currently in use.
C89835 Bismuth Tin Bronze (C932 Replacement)
Converting Over To Lead Free Bronze Bushings
Manufacturers, Distributors, Builders, and Plumbers across the country must comply with the Reduction of Lead in Drinking Water Act, affecting all potable plumbing products sold or installed in the United States. Right or wrong, love it or hate it, the “California/Vermont issue” is now the law of the land. We’ve written a whitepaper to help prepare you for this transition. Follow the link below to download the whitepaper.