AGMA has started to replace its 2000-A88 standard for gear accuracy with a new series of documents based largely on ISO standards. The first of the replacement AGMA standards have been published with the remainder coming in about a year. After serving as a default accuracy specification for U.S. commerce in gear products for several decades, the material in AGMA 2000-A88 is now considered outdated and in need of comprehensive revision.
In his Handbook of Gear Design (Ref.1), Dudley states (or understates): "The best gear people around the world are now coming to realize that metallurgical quality is just as important as geometric quality." Geometric accuracy without metallurgical integrity in any highly stressed gear or shaft would only result in wasted effort for all concerned - the gear designer, the manufacturer, and the customer - as the component's life cycle would be prematurely cut short. A carburized automotive gear or shaft with the wrong surface hardness, case depth or core hardness may not even complete its basic warranty period before failing totally at considerable expense and loss of prestige for the producer and the customer. The unexpected early failure of a large industrial gear or shaft in a coal mine or mill could result in lost production and income while the machine is down since replacement components may not be readily available. Fortunately, this scenario is not common. Most reputable gear and shaft manufacturers around the world would never neglect the metallurgical quality of their products.
This section will deal with the use of gear inspection for diagnostic purposes rather than quality determination. The proper evaluation of various characteristics in the data can be useful for the solution of quality problems. It is important to sort out whether the problem is coming from the machine, tooling and/or cutters, blanks, etc. An article by Robert Moderow in the May/June 1985 issue of Gear Technology is very useful for this purpose.
I support Clem Miller (Viewpoint May/June) in his skepticism of ISO 9000. The metrology of gears is important, but in the present state of the art, manufacture is more accurate than design.
Much about ISO 9000 is the subject of noisy debate. But on one thing almost everyone, true believers and critics alike, agrees: Getting ISO 9000 certification can be expensive. Companies can expect to spend at least $35,000 for basic certification and six-month checkup fees over a three-year period. These figures do not include hidden costs like time and money spent on internal improvements required to meet ISO 9000 certification. But the really big-ticket items in the process are employee time and the cost of bringing in outside consultants. Many ISO 9000 consultants charge upwards of $1,800 a day.
On of the key questions confronting any company considering ISO 9000 certification is, how much is this going to cost? The up-front fees are only the beginning. Dissect the ISO 9000 certification procedure with an eye for hidden costs, and two segments of the process will leap out - the cost of consultants and the cost of making in-house improvements for the sake of passing certification. Most of these costs can be controlled by careful selection f the right consultant in the first place.
What follows is the first of three articles we will be running on ISO 9000 and what it means for the gear industry. This first article will cover what ISO 9000 is, what some of its benefits - and problems - are, and whether your company should be a candidate for this certification process. In our next issue, we will consider the important question of how, when, and if to hire an ISO 9000 consultant. The final article in this series will discuss ways to save money while streamlining the certification process in your company.
ISO 9000 is the latest hot topic in marketing and manufacturing circles. Everyone seems to be talking about it, but few seem to understand it completely. depending on whom one talks to, it's either the greatest thing to hit industry since the assembly line, another cash cow for slick consultants, a conspiracy on the part of Europeans to dominate global markets, or the next necessary step to compete in the global economy of the twenty-first century. It may be all of the above.