We have a customer which asks in his tender specification for a product which must have a thickness not exceeding 2±0.3 mm .

what should we offer in this case ?
is it acceptable that i will offer him a product with a thickness of 1.7 mm ?:confused:

well, it seams the thickness of the product should be in the range 1,7 - 2,3mm.
any thickness in this range is OK.

I would prepare something in the middle just to be in the safe side...
yet if you materials are expensive and you can cut on the costs 1,75mm would be economically justified, IMHO.

:2cents:

Aiming for 1.7mm is not a good idea, as it is right on the tolerance limit.yet if you materials are expensive and you can cut on the costs 1,75mm would be economically justified, IMHO.You also need to know the thickness variation to play that game. The example given would work if it stays within +/- 0.05mm.

Also worth noting: 2±0.3 mm is a pretty wide tolerance but it may still be that the part works less well close to a tolerance limit, than close to the nominal thickness 2.00mm.

/Claes

If I reformulate the equation , i have

thickness < [1.7 mm - 2.3 mm] then a value of 1.7 mm and more will be inacceptable ,
I should take a value < 1.6 mm , non ?

If I reformulate the equation , i have

thickness < [1.7 mm - 2.3 mm] then a value of 1.7 mm and more will be inacceptable ,
I should take a value < 1.6 mm , non ?

My feeling is that you have "reformulated" the equation incorrectly. I read the "not to exceed" requirement as needing to be 1.7/2.3 mm.

I agree with gereard and Claus that, without knowing the product and the variability of the manufacturing process, you should probably be targeting 2.0 mm. As with most replies to these types of questions, the safest bet is to ask the customer for clarification. We can theorize all we want at the Cove (and we normally come up with very good "theories":rolleyes:) but the customer has the correct answer.

Taking the formula formally that should be true.
It seams the thickness of the material (taking into account only the requirements of the client) should be below this range. Depending on their understanding of the brackets the max thickness can be 1,6 if they condider the [-brackets to be 'open' - 1,6(9) to be very precise - anything below 1,7, or 1,7 if they find [-brackets to mean 'closed' range.

Any way, I would definitely contact them to check what do they mean exactly. What is the point in asking the thickness to be below some range instead of saying that it should be below some given thickness (here being 1,7mm).

Of course, technological issues need to be taken into account... :)

My feeling is that you have "reformulated" the equation incorrectly. I read the "not to exceed" requirement as needing to be 1.7/2.3 mm....
I expect the customer meant "to fall within the range of 2.0 +/- 0.3", which is what the answers above seem to assume as well. The literal interpretation of "not to exceed 2.0 +/- 0.3" is that zero thickness would be OK, since it does not exceed the specs.
As with most replies to these types of questions, the safest bet is to ask the customer for clarification. We can theorize all we want at the Cove (and we normally come up with very good "theories":rolleyes:) ... This may be a case of poor translation from one language to another, or just a poorly worded spec. Bill hit the nail on ther head - double-check with the customer.

... but the customer has the correct answer.I've certainly known customers to be clueless about what they really want. :lol:

Tim F

the communication with this customer is not so easy ,
He requires that we follow the specification 100% (it seems that his
specification is a national standard and he cannot modify any word of it !)

then i am faced with a mute non understandable specification !
My decision is to offer my thickness in my datasheet in the format :
thickness = 2±0.3 mm
and i produce my product with a thickness 2±0.2 mm .

what do you think ?

this seams reasonable but what if they've meant something else?

what is the country of origin of your client? perhaps you could find some co-national of your clients who could give you a hand with this issue and walk around the issue of translations...

:cool:

good luck any way!

He requires that we follow the specification 100% (it seems that his specification is a national standard and he cannot modify any word of it !) ?Oh, I do not think there is any need to modify the customers specification, but it is easier to get to grips with the customers needs if you know how the product will be used.

My decision is to offer my thickness in my datasheet in the format :
thickness = 2±0.3 mm
and i produce my product with a thickness 2±0.2 mm .

what do you think ?If the requirement is 2±0.3 mm and you can stay within 2±0.2 mm, you should have no problems.

/Claes

Also think about the cost impact on your product. Usually more thickness, means more cost.

To determine what your target should be, you need to know your process capability.

K.

the communication with this customer is not so easy ,
He requires that we follow the specification 100% (it seems that his
specification is a national standard and he cannot modify any word of it !)

then i am faced with a mute non understandable specification !
My decision is to offer my thickness in my datasheet in the format :
thickness = 2±0.3 mm
and i produce my product with a thickness 2±0.2 mm .

what do you think ?

Hello Libnani,

Lately, we've had quite a few interesting discussions here at The Cove regarding specifications and interpreations. Any drawing should state what standard (ISO, ASME or other) is to be used when interpreting the specifications.

For example: ASME Y14.5M-1994 states (page 4 Clause 1.4 Fundamental Rules, d): "Dimensions shall be selected and arranged to suit the function and mating relationship of a part and shall not be subject to more than one interpretation."

What do you think?

Stijloor.

We have a customer which asks in his tender specification for a product which must have a thickness not exceeding 2±0.3 mm .

what should we offer in this case ?
is it acceptable that i will offer him a product with a thickness of 1.7 mm ?:confused:

Notwithstanding all of the other responses so far, the specification is contradictory, and you shouldn't accept it until it gets cleared up. Is it OK for the thickness to be less than 2+/-0.3? Do you see how it doesn't make any sense? It's like advertising we see sometimes: Save up to 40% and more!!

the communication with this customer is not so easy...

I'm not trying to derail this thread, but that statement makes me shiver. The inability to communicate effectively with a customer could (and probably will!!) turn out very costly to your organization and I would certainly be working on that.

I'm not trying to derail this thread, but that statement makes me shiver. The inability to communicate effectively with a customer could (and probably will!!) turn out very costly to your organization and I would certainly be working on that.

I do agree!!!

:(

The problem comes from this customer because of his ignorance and his inability to communicate .

Our communication with other clients is very good , we had many methods

to measure their satisfaction (survey , claims , visits ,...) .

I'm coming into this thread as of late.

What is your capability? How accurate can you measure this product? Why not just state what your capability is (assuming that it is well within the specification. Are you 95-99% sure you're within that specification?)

If this is coming from a National Standard, it should not be a secret how to interpret this (unless it is a brand new specification). There should be assistance within the regulatory body on what these specifications mean, and how to interpret them.

the communication with this customer is not so easy ,
He requires that we follow the specification 100% (it seems that his
specification is a national standard and he cannot modify any word of it !)

then i am faced with a mute non understandable specification !
My decision is to offer my thickness in my datasheet in the format :
thickness = 2±0.3 mm
and i produce my product with a thickness 2±0.2 mm .

what do you think ?

Define "exceed". It does not necessarily just mean "to be greater than"
1 : to extend outside of <the river will exceed its banks>
2 : to be greater than or superior to
3 : to go beyond a limit set by <exceeded his authority>

In this case, I would suggest "exceed" means the same as definition 1 or 3, which would mean deviation outside of the limit 2±0.3 in either direction is not acceptable.

Define "exceed". It does not necessarily just mean "to be greater than"
1 : to extend outside of <the river will exceed its banks>
2 : to be greater than or superior to
3 : to go beyond a limit set by <exceeded his authority>

In this case, I would suggest "exceed" means the same as definition 1 or 3, which would mean deviation outside of the limit 2±0.3 in either direction is not acceptable.

In each of the cases you cite, "exceed" means to be greater than some limit or previous state. In the case of the river, it can't "exceed" its banks by going below them (because the new level creates a larger bank); in the case of #3, "exceed" is never used to describe someone using fewer powers or less authority.