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A guide to specifying dies that combine lowest production cost and highest quality, from a company with fifty years' experience as both tool builder and
stamper.
Want to be the least-cost producer on every job you bid, and be consistently on-spec in the bargain?
Memorize these three words: Quality. Uptime. Serviceability. They are essential to controlling die costs. And the meaningful measure of your tooling
investment is not what you pay to build a die, but what you pay to run it. That is why quality, uptime and serviceability are so important: They determine the true cost
of die operation. Least-cost manufacturing begins with the tooling, which must provide consistently high quality and production rates, and rapid, simplified
maintenance.
M A Metal is both a tooling manufacturer and a custom stamper, specializing in high-production components, primarily for automotive, consumer products, and
building applications. Balancing the demands of die making and press working is a way of life at this, Indiana, firm. If you have a die that requires a lot of
maintenance because it's either poorly built or too complicated to service economically, the piece-part cost skyrockets. The wise die purchaser goes to a toolmaker that
knows how to build economies of operation into the tool, through better materials, easier adjustments in operation, and simplified maintenance. You have to know what the
part volume will be. If you have a long-running, high-volume job, you want to include as many maintenance and adjustment features as possible. For example, punches can
be designed for rapid access for sharpening and polishing. In designing dies, we don't hesitate to use different tool steels if we think it will be a benefit.
Modular die construction is a good way to reduce downtime. Separating a complex tool into several modules makes maintenance more efficient, because
individual modules can be serviced without removing the entire tool from the press. Modular construction can add to the cost of the die, but it can also lower the
finished piece-part cost. Your tooling will include these refinements, only if you ask for them and if you give your tool builder specific requirements of the finished
part. The toolmaker needs to know which dimensions, tolerances and details are critical to making a functional part. The toolmaker also needs to know the [Production]
life expectancy of the part and the number of pieces per year. This information indicates the quality and durability that will be needed in the tool, and it's critical
to getting a realistic tooling quote. As a tool builder, we want to become involved as early as possible in the design process. More and more companies are going to
early vendor involvement, in which the toolmaker meets with the OEM product design team. Input from the die builder can engineer many manufacturing difficulties out of a
part during the design phase. It's very costly to rework a part once the design is finalized. Early involvement generally results in more a cost-effective finished
product. Early involvement tends to eliminate costly over-engineering by identifying which dimensions and tolerances are critical to a component's function. But that
frequently means pointing out mistakes to a client. How does a toolmaker suggest that some tolerances are unnecessarily tight? Very tactfully, they agreed. The best way
is to show that building the die to produce [the demanding] tolerances will cost X dollars. Then suggest that by opening up tolerances at various points, the die will
cost Y dollars less. Here's where understanding the function of a part is important, because the toolmaker can recognize which tolerances are too high. A tooling design
engineer is the most qualified person to make those recommendations.
Is it helpful for a die shop to have a design engineer? Absolutely. Design expertise is another way to give customers a quality die that will make
quality stampings. It's unlikely that small tool shops can afford staff engineers, but they should retain qualified consulting engineers. If I were a stamper dealing
with tool and die shops that had no access to design engineers, I would send my jobs to my own [consulting] engineer. The finished designs would go to the tool shops for
quotes. Having established designs is the only way to compare quotes. [Without it], if you go to four toolmakers, you'll get four entirely different concepts of what
that tool should be. The tooling design engineer is an important resource for both. That is true only if the engineer is qualified to make these high-dollar
recommendations. Establishing an individual's competence is largely a matter of personal experience, and the proliferation of computer-aided design has made evaluating
engineers more difficult. Before CAD, one indication of a good designer was the quality of the line work. That said a lot about the care that was taken . quality of the
line work. That said a lot about the care that was taken with the rest of the project. If the drawings looked careless, it was likely that the calculations were also.
With CAD, everyone's drawings look crisp and clean, and all of the computations are correct even if they don't work in practice. You can have technically correct dies
that don't earn profits. CAD cannot create expertise. But it does allow the established expert to concentrate on the concept and not be mired in repetitive calculations.
If you employ the services of a tooling design engineer, remind yourself that it is to reduce your overall piece part cost. Following a designer's recommendations will
not necessarily result in a low-cost die, and you will pay for the technical services. For many stampers, this prospect is less than thrilling. Remember when you'd go to
the gas station, and you could help yourself to the tire pump? Nowadays, you generally need to put a quarter in the slot to inflate a tire. People don't like that, and
it's the same with engineering. They want free air, and they want free engineering. It is also essential to build a base of die builders with whom you've done business
and with whom you've been satisfied. People who think in terms of making your business successful. Most stampers develop a rapport with die shops that have provided good
service in the past, and those are the vendors they return to. You can't afford to buy tools strictly on price every time. We know some of the suppliers by reputation;
others we've worked with over the years. On more complicated jobs, We will design the die and send it to them to build; on simpler jobs, we contract with them to create
the design. If you are making a cold search, the Thomas Register is a standard reference.
Advice for the stampers! You're generally on your own searching for tooling sources, because it's very difficult to get recommendations from other
stampers. They are, after all, your competitors, and don't want to share their best sources. Make a list of the shops that seem to fit your needs, then place telephone
calls. Describe your part, and see who's interested. When someone says "Yes, your part fits our capabilities; let's talk," you request a formal quote. In addition to
capabilities, look at the company's longevity and track record. This isn't to suggest that new shops aren't good, but you want to deal with people who have a solid
background. That may be the factor that recommends one shop over another. Once you're satisfied with the price, you should visit the die shop and ask questions. "Show me
some of the tooling that you've built; show me sample parts from that tooling. The toolmaker is also evaluating you. What is your history? Are you an organization it
wants to become involved with? This process is necessary if you are to match your project with the die maker's capabilities. One of the worst situations is for a tool
builder to take on a part for which it really isn't qualified. Sometimes, the most helpful thing a die maker can do is turn you down. File that supplier's name for
future reference. It has earned your consideration when you have a project that is a match. Conscientious tool builders will request permission to refer your job to
someone else if they know of a shop that's more qualified. Toolmakers know the capabilities of other companies, and the reputable ones generally willing to make
recommendations. A rejection by one supplier can lead to a very profitable relationship with another.
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