Lead-free Cast Red Brasses for Plumbing
Besides faucets, like this one, the new brasses will find uses in valves, backflow preventers, water meters and other hardware.The U.S. Government requires the water Americans drink to be free of health threatening lead as much as possible. To help meet this imperative, as defined in an ANSI/NSF standard, the Copper Development Association has been participating in a major effort to develop lead-free, cast red brasses for plumbing fixtures.
The initial happy result is SeBiLOY I and SeBiLOY II, which substitute selenium and bismuth for lead.
PrimaryElementsSEBILOY I
| Compositions of SEBILOY 1 and SEBILOY II | ||
| Range or max., % | ||
| SEBILOY II | ||
| Copper | 86.0-88.0 | 85.0-87.0 |
| Tin | 4.0-6.0 | 4.0-6.0 |
| Lead(1) | 0.25 | 0.25 |
| Zinc | 4.0-6.0 | 4.0-6.0 |
| Bismuth | 0.5-1.5(2) | 1.5-2.50(2) |
| Selenium | 0.35-0.7(2) | 0.8-1.2(2) |
| Nickel (incl. Cobalt) | 1.0 | 1.0 |
| (1) Trace amounts up to 0.25% may be present; levels may be specified when purchasing. (2) BiSe ratio ≥ 2:1 |
||
SeBiLOY II contains roughly twice as much of the key elements as SeBiLOY I. These lead-free red brasses are comparable to the cast leaded red brasses in key characteristics: machinability, pressure tightness, casting, soldering, brazing and plating. Besides faucets, the new brasses will find use in valves, backflow preventers, water meters and other hardware.
There are other health and cost benefits to SeBiLOY I and II: when machined dry (without cutting fluids), no significant lead-bearing particles enter the machine shop air. This means no special air purification equipment is needed, enabling a possible drop in insurance costs for manufacturers of plumbing fixtures because their workers won't be exposed to lead. In addition, for sand casters, the costs for prevention of airborne lead and for reclamation and disposal of foundry sand should be lower.
No Toxicity Worries
Bismuth was identified early on as a likely substitute for toxic lead; it's a neighbor of lead on the periodic table of elements. That bismuth is not toxic to humans (unless consumed in immense quantities) is proven by the fact that it's an ingredient in preparations like Pepto-Bismol taken to cure upset stomachs.
Selenium enhances the effect of bismuth, reducing the amount needed to achieve the desired improvement in properties. And, it is also not toxic; many take selenium supplements because, like copper, it is an essential nutrient.
Some shops machining the SeBiLOY alloys may experience slightly higher tool wear compared with either C83600 or C84400. Compared to a machinability rating of 100 for free-cutting brass (C36000), SeBiLOY I and II have ratings of 75 and 85, respectively. In addition, CDA recommends applying cooling liquids during the polishing of products made of SeBiLOY to prevent polishing defects from pullout of the low-melting bismuth particles.
Alloy| Machinability Ratings | |
| Machinability Ratings (Multiple Operations) |
|
| C3600 (Free-Cutting Brass) | 100 |
| C83600 | 84 |
| C84400 | 90 |
| SeBiLOY I (C89510) | 75 |
| SeBiLOY II (C89520) | 85 |
SeBiLOY brasses exhibit machined surface quality and finish equal to or better than that of traditional leaded brasses. And they are actually superior to the leaded brasses in hot tearing at abrupt section changes. For manufacturers who need a lead-free yellow brass for the permanent mold casting process, research is currently underway on a new, lead-free yellow brass called SeBiLOY III. It should be available late this year.
One of the first users of the SeBiLOY alloys is The Chicago Faucet Company, Des Plaines, Illonois. According to Charles Davis, a manufacturing engineer, all of the company's products will now be made of these lead-free red brasses.
The SeBiLOY brasses were developed by a consortium comprising a broad cross section of the plumbing products industry, including CDA, the Brass and Bronze Ingot Manufacturers (BBIM), the American Foundrymen's Society, several faucet producers and a number of copper alloy foundries. The alloys are available free of license and royalty fees of any kind.
The SeBiLOY brasses are about 50% more expensive than the leaded brasses they replace, according to Mark Schumann. He is president of BBIN4 and chairman of 1. Schumann & Co., Bedford, Ohio, a supplier of copper alloy ingots.
Eight other companies currently can supply SeBiLOY brasses, too:
- The G.A. Avril Company - Cincinnati, Ohio
513-641-0566 - N. Kamenske & Company, Inc. - Nashua, New Hampshire
603-882-5113 - W.J. Bullock, Inc. - Fairfield, Alabama
205-788-6586 - Kearny Smelting Refining Corp. - Kearny, New Jersey
201-991-7276 - Colonial Metals, Inc. - Columbia, Pennsylvania
717-684-2311 - R. Lavin & Sons, Inc. - Chicago, IL
312-847-1800 - Sipi Metals Company - Chicago, IL
312-276-0070 - National Metals, Inc. - Leeds, Alabama
205-699-5191
SeBiLOY I and II are not the only lead-free brasses. Two years ago, The Federal Metal Company, Bedford, Ohio, introduced its lead-free "Federaloys," for which it obtained a patent in July 1994. According to President David Nagusky, Federal has sold "millions of pounds of the Federaloys," which come in three versions containing 1%, 2% and 3% bismuth, repectively. Three firms ha licensed to produce Ingot Metal Co., Toro Smelting & Refining Cleveland; and Sipi Corp., Chicago. Sever overseas suppliers are also offering lead-free plumbing brasses with compositions that also utilize bismuth to replace the lead.
- Chicago Faucet - 8471803-5000
- The Federal Metal Company - 216232-8700
- I. Schumann & Co. - 800321-8702
Also in this Issue:
- Lead-free Cast Red Brasses for Plumbing
- Copper Alloys Favored for Connectors
- Copper and Brass Make a Silver Ghost!
- Copper Covers U.S. Olympic Training Center