"Global" GD&T Standard? 2

[hygear]

I work in a regional (U.S.) development office for a Japanese company. We primarily design parts to be sourced from local suppliers and use the ASME Y14.5M standard for most of our drawings. We also source many parts from Italy, Spain, Japan and China but most of these drawings do not use GD&T. Recently our Japanese manager has requested that we determine a single standard for drawings so that anyone in the world can understand them. Unfortunately, he's leaning towards our internal standards as the way of doing things so I'm trying to gather up some more information to determine what is the best "Global" standard for GD&T. Here are a few of the issues/concerns that we have:

1. We are encouraged to use the internal standard even though we believe it is wrong. It allows things like concentricity between two parts (instead of a single solid of revolution), position with no datum references, it allows diameter symbols on things like flatness, it doesn't allow the use of MMC, and we are discouraged from using more than a couple of datums (even on parts where 5 or 6 datums would be ideal).
2. All of the engineers in this office understand the ASME standard and a few even have the certification. Unfortunately, we are told that virtually all Chinese suppliers and most Japanese suppliers don't understand the ASME standard.
3. We understand that the ISO standard is similar to ASME, but aren't clear of the differences/similarities because we do not have a copy of the standards. We use ISO design/safety standards for pretty much everything else, so it makes sense to me to use the ISO standard for GD&T as well.

Can anyone provide feedback on what standard is best for this situation?

 

[CheckerHater]

The Master plan document lists 37 others in the bibliography. If the average is near $100 each, that's between $3000 and $4000 dollars for the set, though some are inspection methods docs, so maybe only $2000 to replace Y14.5.

Y14.5 does not cover several topics described in master plan. To compare apples to apples you have to look at Y14.100 - how many standards it contains and how much it costs. Then the difference won't be that substantial.

"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future

 

[3DDave]

That's why I excluded almost half of the Master Plan. As I mentioned, ISO 5459:2011 Datums and datum systems are 81 pages and 198 swiss francs or 210 US Dollars, which by itself is more that the ASME Y14.5 specification, currently $185.

This is referring only to ISO 14638:2015(en) Geometrical product specifications (GPS) — Matrix model, which does not include drawing management. It does include inspection methods, which I tried to estimate an exclusion of, but with ISO datum referencing alone costing more than the entire ASME Y14.5 Dimensioning and Tolerancing, it is hard to say that any comparison will put them on even footing in terms of cost.

More insidious, there are others required, that are not in this list; ISO 5458:1998(en)
Geometrical Product Specifications (GPS) — Geometrical tolerancing — Positional tolerancing, requires ISO 14660-1:Not Released), Geometrical product specification (GPS) — Geometric features — Part 1: General terms and definitions, which has already been superceded by ISO 17450-1:2011 Geometrical product specifications (GPS) -- General concepts -- Part 1: Model for geometrical specification and verification.


While I can understand why contributing employees of big companies serving on the Y14.5 committee would be compelled to 'harmonize' with suppliers working on the ISO GPS committees, ISO doesn't immediately seem attractive to emulate in any way.

Below is the list from the Master Plan, items pertaining to drawing specification are bolded, but these are only from the Master plan and do not include all drawing creation GPS standards.

[1] ISO 286-1:2010, Geometrical product specifications (GPS) — ISO code system for tolerances on linear sizes — Part 1: Basis of tolerances, deviations and fits
[2] ISO 286-2:2010, Geometrical product specifications (GPS) — ISO code system for tolerances on linear sizes — Part 2: Tables of standard tolerance classes and limit deviations for holes and shafts
[3] ISO 463:2006, Geometrical Product Specifications (GPS) — Dimensional measuring equipment — Design and metrological characteristics of mechanical dial gauges
[4] ISO 1101:2012, Geometrical product specifications (GPS) — Geometrical tolerancing — Tolerances of form, orientation, location and run-out
[5] ISO 1660:1987, Technical drawings — Dimensioning and tolerancing of profiles
[6] ISO 1829:1975, Selection of tolerance zones for general purposes
[7] ISO 1938-1, Geometrical product specifications (GPS) — Dimensional measuring equipment — Part 1: Plain limit gauges of linear size
[8] ISO 2692:2006, Geometrical product specifications (GPS) — Geometrical tolerancing — Maximum material requirement (MMR), least material requirement (LMR) and reciprocity requirement (RPR)
[9] ISO 3040:2009, Geometrical product specifications (GPS) — Dimensioning and tolerancing — Cones
[10] ISO 3274:1996, Geometrical Product Specifications (GPS) — Surface texture: Profile method — Nominal characteristics of contact (stylus) instruments
[11] ISO 3650:1998, Geometrical Product Specifications (GPS) — Length standards — Gauge blocks
[12] ISO 4287:1997, Geometrical Product Specifications (GPS) — Surface texture: Profile method — Terms, definitions and surface texture parameters
[13] ISO 4288:1996, Geometrical Product Specifications (GPS) — Surface texture: Profile method — Rules and procedures for the assessment of surface texture
[14] ISO 5458:1998, Geometrical Product Specifications (GPS) — Geometrical tolerancing — Positional tolerancing
[15] ISO 5459:2011, Geometrical product specifications (GPS) — Geometrical tolerancing — Datums and datum systems
[16] ISO 8015:2011, Geometrical product specifications (GPS) — Fundamentals — Concepts, principles and rules
[17] ISO 10360 series, Geometrical product specifications (GPS) — Acceptance and reverification tests for coordinate measuring machines (CMM)
[18 ISO 11562:1996, Geometrical Product Specifications (GPS) — Surface texture: Profile method — Metrological characteristics of phase correct filters
[19] ISO 12085:1996, Geometrical Product Specifications (GPS) — Surface texture: Profile method — Motif parameters
[20] ISO 12181-1:2011, Geometrical product specifications (GPS) – Roundness – Part 1: Vocabulary and parameters of roundness
[21] ISO 12181-2:2011, Geometrical product specifications (GPS) — Roundness — Part 2: Specification operators
[22] ISO 12780-1:2011, Geometrical product specifications (GPS) — Straightness — Part 1: Vocabulary and parameters of straightness
[23] ISO 12780-2:2011, Geometrical product specifications (GPS) — Straightness — Part 2: Specification operators
[24] ISO/PAS 12868:2009, Geometrical product specification (GPS) — Coordinate measuring machines (CMM): Testing the performance of CMMs using single-stylus contacting probing systems
[25] ISO 13385-1:2011, Geometrical product specifications (GPS) — Dimensional measuring equipment — Part 1: Callipers; Design and metrological characteristics
[26] ISO 13385-2:2011, Geometrical product specifications (GPS) — Dimensional measuring equipment — Part 2: Calliper depth gauges; Design and metrological characteristics
[27] ISO 13565 series, Geometrical product specifications (GPS) — Surface texture: Profile method; Surfaces having stratified functional properties
[28] ISO 14253 series, Geometrical product specifications (GPS) — Inspection by measurement of workpieces and measuring equipment
[29] ISO 14253-1:2013, Geometrical product specifications (GPS) — Inspection by measurement of workpieces and measuring equipment — Part 1: Decision rules for proving conformity or nonconformity with specifications
[30] ISO 14405-1:2010, Geometrical product specifications (GPS) — Dimensional tolerancing — Part 1: Linear sizes
[31] ISO 14405-2:2011, Geometrical product specifications (GPS) — Dimensional tolerancing — Part 2: Dimensions other than linear sizes
[32] ISO 15530-3:2011, Geometrical product specifications (GPS) – Coordinate measuring machines (CMM): Technique for determining the uncertainty of measurement – Part 3: Use of calibrated workpieces or measurement standards
[33] ISO/TS 15530-4:2008, Geometrical Product Specifications (GPS) — Coordinate measuring machines (CMM): Technique for determining the uncertainty of measurement — Part 4: Evaluating task-specific measurement uncertainty using simulation
[34] ISO/TR 16015:2003, Geometrical product specifications (GPS) — Systematic errors and contributions to measurement uncertainty of length measurement due to thermal influences
[35] ISO 16610 series, Geometrical product specifications (GPS) — Filtration
[36] ISO/TS 23165:2006, Geometrical product specifications (GPS) — Guidelines for the evaluation of coordinate measuring machine (CMM) test uncertainty
[37] ISO 25178-601:2010, Geometrical product specifications (GPS) — Surface texture: Areal — Part 601: Nominal characteristics of contact (stylus) instruments

 

[CheckerHater]

I do not insist that ISO is all warm and fuzzy.

But I can imagine that it is actually better to get approved and released changes for small part of a big standard within couple of years rather than wait 20 years for the next Y14.5 release.

On the number of standards - see the enclosed list of mostly outdated by now standards forming what they called "Technical Product Specifications"

And on the matter of price - all the standards on the list used to be available on CD ROM for about 350 Swiss francs.

"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future

 

[dgallup]

I would much rather deal with one large standard that gets infrequently revised than to have to try to keep up with dozens of small standards being frequently revised. If they are truly STANDARDS they should not be revised. If I call them out on my drawing and the interpretation changes then my product definition may have changed. The product that has undergone rigorous testing and validation may no longer meet it's requirements. It's bad enough when it's only every 20 years and it's all in one document, at least we can have a date with a sharp cut off. It's unacceptable when little bits change here and there every year. Who can keep track of the net effect of dozens of unconnected little changes?

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The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.

 

[ewh]

That is why the version needs to be included wherever a specification is noted.

"Know the rules well, so you can break them effectively."
-Dalai Lama XIV

 

[pmarc]

Without going too deep into details, I just wanted to say that selection of dimensioning and tolerancing standard definitely should not be a "just like that" decision. Many things need to be considered, and in my opinion things like cost of particular package of standards are not on the top of the list.

Using one of the examples given by juergenwt, it is absolutely true that Euro was introduced overnight, but this was just a final effect of a huge process that had started many years before - way before anybody even knew that the common currency will be named Euro.

 

[juergenwt]

True - The Euro was introduced 1. Jan. 1999. The move to a common European currency started much earlier but did not gain traction until German re-unification in 1990.
However - after years of preparations most national European currencies changed overnight to the Euro. Success!

Sorry - the following is a little bit off topic but it does kind of fit in with the discussion on standards. Just like trying to conform to ISO.

Compare this (the change over to the Euro) with the change from imperial to metric in the UK. Thirty years and they are still fighting it day by day!
Same thing in the US. Our vote counting politicians will be insisting on a change over the next 10, 15, 20 years and on and on. In the mean time the country suffers and our manufacturing sector has to fight this every day. With the right preparation this could be achieved in an overnight move! The emphasis is on PREPARATION! Than you do it!!
Next morning you wake up and TV reports the temp. in deg.Celsius. Your train schedule has changed to 24 hour clock. The street signs are in km - not km and miles. Your paper format changes from letter size to A4. Schools teach metric - and metric only! No more " over the next 5 years" . Period!
I would predict - this would go over better than anybody anticipates except for the nuts who worry about the inch worm.
Than - may be - we could all agree to manufacture to ONE standard. Would that be nice?