How to measure "1 in 20 parts"
How to measure "1 in 20 parts"
(OP)
I work in a foundry, and a customer of ours required 1 in 20 pieces be tested for mechanical properties. We can only pour 8 pieces at a time, and have no serialiation to identify "this is the 20th piece, this is the 40th piece"
How the heck can we know when 20 pieces have been made when anyone only ever sees 4 or 8 pieces at a time, interspersed between dozens (sometimes hundreds) of other parts?
I know serialization may be the answer, but I've been told that "is not a viable option at this point" . . .
How the heck can we know when 20 pieces have been made when anyone only ever sees 4 or 8 pieces at a time, interspersed between dozens (sometimes hundreds) of other parts?
I know serialization may be the answer, but I've been told that "is not a viable option at this point" . . .
RE: How to measure "1 in 20 parts"
How do you provide the parts to your customer? I bet the shipping department knows how many parts go out the door.
Worst case scenario, you estimate how long it takes to make/send 20 pieces and take one from that time period for your testing.
Regards,
Cory
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RE: How to measure "1 in 20 parts"
"Art without engineering is dreaming; Engineering without art is calculating."
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RE: How to measure "1 in 20 parts"
One piece in 20 is overkill for sure.
Dave D.
www.qmsi.ca
RE: How to measure "1 in 20 parts"
These are very large castings (450 lbs) and 8 is the most we have the capacity to pour at once ie one heat = 8 pieces MAX
MadMango -- I considered your option, but that is alot of added cost, testing more than twice what the customer requires. If anything I would ask if we could test one per order, which is likely less than 1 in 20.
dingy2 -- the only mechanicals we check per heat is hardness. The #1 thing we produce is wear parts for mining applications, so most of our customers are more concerned with wear performance then tensile strength or anything else which is why these types of requirements are new to us.
RE: How to measure "1 in 20 parts"
I remember a long time ago, we would surface grind with a hand grinder the brinnelled area and then had a portable machine and it worked out pretty well.
I can understand the customer requirement now.
Dave D.
www.qmsi.ca
RE: How to measure "1 in 20 parts"
Regards,
Cory
Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips Fora.
RE: How to measure "1 in 20 parts"
I once got lectured by a customers QA on how the '1 in 20' should be picked at random.
Your customers requirement may better define this.
KENAT, probably the least qualified checker you'll ever meet...
RE: How to measure "1 in 20 parts"
RE: How to measure "1 in 20 parts"
Since you are providing data to the customer, I also trust/hope you are utilizing the data yourself for feedback into process improvement and control. Make the expense of the testing work for you and add value if possible. If you are consistently able to show the customer that your are meeting or exceeding their requirments, perhaps they would be willing to lower the testing rate.
Regards,
RE: How to measure "1 in 20 parts"
I also agree with the 'golden' job - this is watched by all and sundry, so everyone works exactly to procedure and takes great care. If this is representative of 'normal' production at your place, you are very successful (or lucky!).
My advice is for you to want to understand your job and process, this will give you the knowledge to establish a sampling regime that your customer will hopefully buy into due to your wealth of confidence in the product you make.
By the way, my company insist on mechanical tests for each piece we order. It annoys the supplier but we have little confidence (demonstrated information) from them.
"Help yourself, to help others"