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  for Metal Finishing since 1989
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Quality margins

1998

We are a plant that produce buckles for shoe industry here in leÛn. We have been in the bisness for two year so we don't have all the practical information we like.

our batchs are of 500 pieces each and I want to ask about the size of sample to asegure 0.5% of regrets. in adition with I ask about the procedure to get this.

i also ask about the margin of error in this kind of industry world wide ( 0.05% regrets, or 1 p.p.m) so we can compare how long we have to go on this

Ing. Alejandro Lanzagorta
redi-metal leon,guanajuato, Mexico

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Mr. Lanzagorta,

Are you referring to the reject rate from one operation, such as plating?

If you are barrel plating 500 pieces at a time, assuring a low reject rate will depend heavily on quality control of the plating solutions and physical plant maintenance of the barrels and contact danglers configuration of the buckles and how they nest with each other and as a load tumbling in the barrel margin of error in barrel plating, depending upon the shape of the part, and some of the factors given above can be 100 ppm (rarely) or as much as 100,000 ppm.

  
Tom Pullizzi
Falls Township, Pennsylvania
1998

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Dear Mr Pullizzi:

I appreciate the time you gave to this letter.

i was not as clear as I thougth. I was asking about the quality margin as a plant and not only in finishing operation.

In fact, we have 0.1% error there ( as finishing operation) and we think it's good.

so, I ask you if you can lead us to someone that can help us in this search, because our principal quality problem is porous surface and we are trying to avoid the pieces get finish.

once again thanks for your time

Ing. Alejandro Lanzagorta
redi-metal leon,guanajuato, Mexico
1998