Using Pin Gages as a Measurement Tool for Ppk/Cpk studies

J

jfantao

#1
Hello All

A quick question on capability studies: Can we use pin gages as a measurement tool to do a cpk/pp study?
The dimension in question is a hole: 1.2 +/- .05 mm.

I am thinking no, but I want to confirm with the group before I go and tell our factory (with rationale) that the data collected is not acceptable.

thanks
 
Elsmar Forum Sponsor

ScottK

Not out of the crisis
Staff member
Super Moderator
#2
Re: Gages used for ppk/cpk studies

you can do an attribute capability study with pin gauges.
I suppose for most standard uses pin gauges are not considered variable data...

your measurement is +- .05mm which is about .002" so personally I feel that depending on what the increments your pin gauge set is at I don't see how pin gages won't give you similar information as a measuring tool that's accurate to .0005".

besides - how else would you measue a 1.2mm hole?
 
Last edited:

Kales Veggie

People: The Vital Few
#3
Re: Using Pin Gages used for ppk/cpk studies

For a capability study on hole size, you would need variable data.

1) Pin gauge will tell (when the pin goes in the hole), that the hole is larger than the pin.
2) The next larger pin does not go in the hole. The hole size is smaller than the pin.
3)You could use the average of the two pins (fit and notfit) for the hole size, but it is not accurate.
4)Quiet sure that the capability calculated is not accurate (probably lower, because the method introduces more variation).

Hope this helps. BTW. Using pin gauge for a study like this would be time consuming also.
 
G

Gary E MacLean

#4
Re: Gages used for ppk/cpk studies

you can do an attribute capability study with pin gauges.
you can also do variable studies. Just use the applicable set of pin gages. They do make pin gages in four decimal places. Even a three decimal place pin gage is as accurate as an inside caliper or something.
 

ScottK

Not out of the crisis
Staff member
Super Moderator
#5
Re: Gages used for ppk/cpk studies

you can also do variable studies. Just use the applicable set of pin gages. They do make pin gages in four decimal places. Even a three decimal place pin gage is as accurate as an inside caliper or something.
that's what I figure... but all customers that we've done capability studies for insist that pin gages are only for attributes.

in process we do "measure" with them because it suits our needs.
 
G

Gary E MacLean

#6
Re: Gages used for ppk/cpk studies

in process we do "measure" with them because it suits our needs.
There is the key..."it suits our needs." Your customers may be thinking, right off the bat, without really thinking, of the typical way a pin gage is used; you know, go-no/go. But if you use every increment from one limit to the other you have variable data. Its the same as the little increments on a dial caliper; better than a dial caliper.

1) The blade on a caliper is approximately 0.025 wide so you have already created a chord rather than a flush measure.

2) Your diameter is small enough (1.2mm) that only about 0.025 of the caliper blade tips can be used, very tricky measure.

3) The diameter is also small enough that the caliper tips will never be in line, you will always be measuring off center.

You simply cannot get as good a measure with a caliper; vernier, dial or digital, as you can with gage pins. Besides, it is always best to do your studies with the gages that will be used in production. (See PPAP Manual)

I used to be product engineer where they made spark plugs; it was a screw machine operation. The metal part of the spark plugs have an ID that the ceramic part sets into. The ID only ranges about 0.008. I had round cores with all increments of the pin gages inserted around the OD, made for variable gaging. Worked like a charm. Each gage looked like a pin wheel but everything was right there in one gage.

Make a gage or do something to "show and tell' your customer. They just have to be convinced.
 
Last edited by a moderator:

Jim Wynne

Staff member
Admin
#7
Re: Gages used for ppk/cpk studies

You simply cannot get as good a measure with a caliper; vernier, dial or digital, as you can with gage pins. Besides, it is always best to do your studies with the gages that will be used in production. (See PPAP Manual)
I think this is generally true, but you have to remember that pins don't tell you the size of the hole. They just tell you the size of the largest pin that will fit in it. In most cases this doesn't matter. Also, it's possible to detect roundness issues with a caliper, which you can't do with a pin.
 
G

Gary E MacLean

#8
Oh Sure, that's true Jim, in larger holes. We are talking about a hole that is smaller than 0.060. True the Pins will do just what you say they do but they will get closer, especially on the smaller holes, than many other pieces of equipment. You could never detect roundness on a 1.2mm hole with a caliper.:cool:
 
G

Gary E MacLean

#10
Certainly, air gaging or light gaging would both be better, more accurate and thorough. Run a price comparison on the three methods though and see which one still looks the best.

There is always a better way but when does the cost outweigh the benefit?
 
Thread starter Similar threads Forum Replies Date
D Calibration of Pin Gages using a Calibrated Caliper that measures to 4 decimal places General Measurement Device and Calibration Topics 15
Marc Accuracy & Explosive Bolts - Using pin gages to measure reamed holes General Measurement Device and Calibration Topics 8
Q How can you justify using a more accurate Pin Gage class? General Measurement Device and Calibration Topics 16
C Using a Pin Gage to check True Position of Inline Holes, Design, Tolerance. Etc Inspection, Prints (Drawings), Testing, Sampling and Related Topics 1
S GR&R for Dowel Pin Holes Using Deltronics Pins Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 9
C Pin Gauge Calibration using a Micrometer - Accuracy & Calibration Level Question General Measurement Device and Calibration Topics 10
D Using electronic lab notebooks in the design control process ISO 13485:2016 - Medical Device Quality Management Systems 3
M Using a Non Certified vendor Supplier Quality Assurance and other Supplier Issues 5
H Using/Selling power banks with your product as a "mobile version" CE Marking (Conformité Européene) / CB Scheme 3
cgaro62 Using internal audits as part of document reviews Document Control Systems, Procedures, Forms and Templates 21
R Select the 1 Supplier based on the Parts Durability from 6 Supplier Samples using Minitab Using Minitab Software 11
M MSA angle issue - Nylon parts using Aberlink 3D Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 0
D Question on using audit checklist ISO 13485:2016 ISO 13485:2016 - Medical Device Quality Management Systems 20
J Using of CE marking - Two CE markings on the product CE Marking (Conformité Européene) / CB Scheme 5
R Using R package to implement Bayesian phase I/II dose-finding design for three outcomes ISO 13485:2016 - Medical Device Quality Management Systems 6
S Defibrillator Protection applicability When using Multiple applied parts IEC 60601 - Medical Electrical Equipment Safety Standards Series 0
P Using Zinc Plated Steel in a Cleanroom Other Medical Device Related Standards 3
J Incoming Inspection Records using Excel File ISO 13485:2016 - Medical Device Quality Management Systems 2
J Using ring gauges General Measurement Device and Calibration Topics 2
M Load Cell Calibration using a totalizer on a flow meter General Measurement Device and Calibration Topics 0
P Can Neoprene be Cleaned Using Isopropyl Alcohol (IPA) Manufacturing and Related Processes 4
GreatNate Anyone using the Intellect QMS software? Quality Assurance and Compliance Software Tools and Solutions 1
chris1price Sterilization using beta radiation Other Medical Device Related Standards 2
M Using the phrase "herein referred to" Document Control Systems, Procedures, Forms and Templates 8
B Struggling with using the 5.6 version Ford Capacity Analysis Report APQP and PPAP 5
cnbrosa Study Type 1 on a CMM using a measuring support Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 4
rerusk1 MRB (Material Review Board) Process using MS Sharepoint or MS Teams Manufacturing and Related Processes 2
K 510k FDA review, will they accept Biocompatibility result generated using feasibility product lots? 21 CFR Part 820 - US FDA Quality System Regulations (QSR) 8
B AS9100D 7.1.5.2 Calibration or Verification Method using outside cal lab AS9100, IAQG, NADCAP and Aerospace related Standards and Requirements 1
U Medical Device CE Marking - Using a disposable bearing CE Marking (Conformité Européene) / CB Scheme 3
D Calibration tolerance question using Pipettes Medical Device and FDA Regulations and Standards News 3
D Risk Analysis using Monte Carlo Simulation instead of Scoring and Heat Map Risk Management Principles and Generic Guidelines 2
W Using tailoring guidelines to tailor a QMS procedure ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 2
Y We found out we have been using a equipment without validation for past 4 years Quality Manager and Management Related Issues 6
D Using Laboratory Notebooks in R&D and Design and Development ISO 13485:2016 - Medical Device Quality Management Systems 3
C Importer shell game - Using a third party logistics provider (3PL) in the EU EU Medical Device Regulations 5
S Work performed in Canada on US patients using US device Canada Medical Device Regulations 1
S Is using ANSI/ASQ Z1.4-2008 the correct sampling plan to determine Pass/Fail of Apparel measurements? AQL - Acceptable Quality Level 4
A What are the pros and cons of using an audit software for internal auditing? General Auditing Discussions 7
Tagin Evaluating nonconformances for escalation using Bayesian methods? Statistical Analysis Tools, Techniques and SPC 2
D Using non-conforming components even though the final assembly is conforming? Manufacturing and Related Processes 5
B Using Unreleased Documents & Process Maps for Internal Audit purposes ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 12
R Clause 7.7 Replicate, Recalibration and Intermediate checks using Artifact ISO 17025 related Discussions 1
Stoic Are any medical device companies using the 2011 FDA process validation guidance instead of GHTF/SG3/N99-10:2004? 21 CFR Part 820 - US FDA Quality System Regulations (QSR) 1
B Unit of Use DI (Device Identifier) - Products using the same device US Food and Drug Administration (FDA) 0
A Using Arduino based sensors for Poke-Yoke Manufacturing and Related Processes 6
M Using your Manufacturer's ISO certification ISO 13485:2016 - Medical Device Quality Management Systems 5
Ed Panek Adverse Event Clinical Trial using a 510K approved Device Other US Medical Device Regulations 6
B Using non CE parts in a machine CE Marking (Conformité Européene) / CB Scheme 1
G Gauge R&R on multiple dimensions using 3D measurement system Capability, Accuracy and Stability - Processes, Machines, etc. 6

Similar threads

Top Bottom