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| Stainless steel bolts and rivets cold formed by John Hassall, Inc. Parts at the top are copper coated, those in the middle are coated with KnightCote™ coating. Parts at bottom have had coating removed. |
WESTBURY, NY, USA - (June 24, 2004) – John Hassall, Inc., a Long Island specialist in custom formed and machined parts, has harvested big rewards by re-evaluating and changing coatings used in the shop’s cold forming operations.
Since John Hassall decided to employ an environmentally-friendly coating instead of conventional copper coating on its stainless steel heading wire, it has (a) reduced coating removal time by one half or less compared with the time required for copper removal, (b) eliminated the headaches and costs associated with copper solution disposal, (c) improved heading tool life, and (d) increased productivity with the time saved in cleaning. All of this was accomplished without compromising the high quality of parts produced.
The wire coating with the environmental advantage, known as KnightCote™ wire coating, has been developed by Carpenter Technology Corp., Reading, PA (NYSE:CRS) to perform with high efficiency in both cold and warm heading operations in many alloy systems, conditions and applications. It is a relatively thin and adherent coating that can be applied uniformly on any heading-grade wire produced at the company’s mill.
John Hassall, always on track to reduce costs, has specified that KnightCote coating be applied on all stainless steel wire from the mill. The shop forms all of its stainless steel parts from alloys that include stainless types 302, 302HQ, 347, 410, 416, 418, 434, 440 and Carpenter stainless No. 10.
When the company used copper coated heading wire, it had to remove the copper from finished parts in either a tumbling barrel or a vibratory bowl, augmented in both cases with a mild nitric acid solution. It took 30 minutes to one hour to clean a batch of parts. Larger parts with thicker cross sections were generally treated in the tumbling barrel, which is a more aggressive cleaning process. Smaller, more delicate parts with fine threads and critical edges that needed to be preserved were treated in a vibratory bowl.
After tumbling or vibration, parts made from copper-coated wire had to be immersed in a nitric acid bath. The tank then contained two effluents – copper and nitric acid – that had to be disposed of, at considerable expense and with great care. Contents of the tank eventually had to be separated, filtered and placed in drums, in accordance with EPA and local code regulations, for pick up by approved professional disposal agencies.
Parts produced from KnightCote-coated wire also have been treated in a tumbling barrel or vibratory bowl, but in a much shorter time and without the cleaning assistance of nitric acid solution. With coating removal time shrunk, skilled employees are free to perform other tasks. Also, parts are easier to handle and ready sooner for delivery to customers.
Best of all, after parts are treated in a tumbling barrel or vibratory bowl, the KnightCote coating can be removed easily and thoroughly in agitated alkaline detergent solutions. These are environmentally-friendly solutions that can be emptied into municipal sewer systems.
Now, nitric acid tanks are unnecessary. Separation, filtering, loading into drums, disposal procedures and paperwork, abiding concern with meeting regulatory requirements are all eliminated. These operations are nothing but time-consuming and expensive.
When Hassall used copper coating on its heading wire, it had to deal with copper-containing sludge which mixed with lubricants and packed into heading dies, rendering them inefficient. This buildup in the dies had to be removed, with machinery shut down at considerable cost and delay.
Carpenter’s KnightCote coating can be used as a stand-alone coating over bare wire, or as an addition to copper coated wire. When used without copper, as it has been at John Hassall, the coating eliminates the need for cleaning acids, which carry metal ions. These metal ions can form NOX, a mixture of nitrogen oxides capable of causing smog and acid rain.
Wire with KnightCote coating can be considered for use in heading and forming operations that require high production rates, severe forming or extrusion. It has been used to produce a variety of fasteners with a wide range of difficulty in upsetting and extrusion.
This environmentally-friendly coating is applied at Carpenter’s mill by a proprietary process that results in minimal variation within or between coils. The coating can be used in a higher-temperature forming process than typical molybdenum disulfide-type coatings.
While looking at coatings as a potential means of improving processes and reducing costs, Akm Chowdhury, Manager, Metallurgy & Material Test Lab, at John Hassall observed that his company maintains a constant vigil over costs as an ongoing commitment to customers.
"Every job shares one important similarity," he said. "That is the need to reduce costs wherever possible without sacrificing quality. As parts get more complex," he added, "the process of cleaning and handling has become more critical."
Chowdhury noted also that his shop is constantly alert to machining operations that are slow, or generate "too much scrap". He described as a company hallmark its ability to convert a machining operation exhibiting those detrimental characteristics into a more efficient, more profitable cold forming operation.
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For more information about Carpenter’s KnightCote™ coating or other Carpenter alloys, you may access the company’s technical database at www.cartech.com.
For more information about John Hassall contact Akm Chowdhury at: phone (516) 334-6200 ext 413; fax (516) 334-6343; e-mail akmc@Hassall.com or sales, Alex J. Smith, VP; Tom Matura, VP (Aero); Dave Lax, VP (Comm) at e-mail: www.hassall.com
