Fixture Gage R&R - What is Required? Fixture part of the measurement system?

R&R What is required?

  • Required

    Votes: 3 75.0%
  • Not required

    Votes: 1 25.0%

  • Total voters


I recently started to evaluate the requirements of QS9000 in relation to R&R studies. If Fixtures are used to "hold" or locate a part in order to obtain a reading(for a destructive test or get a indicator reading),would that Fixture be part of the measurement system that would require a R&R study?:smokin:
Last edited by a moderator:
Elsmar Forum Sponsor


Fully vaccinated are you?
If you are deriving your measurements from a part in a fixture, yes. You have to do the R&R on the combined fixture with the operators.

Let's say, for example, you have a fixture that has 6 gages attached for 6 different dimensions on a part. Each measurement gets the treatment with fixtured parts.


Although I agree with Marc - if the fixture relates to the measurement (i.e. a load cell for torque/tension) it would constitute part of the measurement system, I disagree that all fixtures need to be included in the R&R.

Say for example a bolt had to be held in place while a torque measurement was taken. The torque measurement device is what needs the R&R. The bolt could be held in a variety of ways and as long as it is securely held, it wouldn't matter what held it. It could be a bench vise or a fancy specialty block.

Obviously, something has to be used in the R&R to hold the part. It would stand to reason that it would be the same thing you use in actual practice but there are many instances where the actual fixture is not available for use in a MSA study. In such an instance, IMHO it would be acceptable to "replicate" the fixture.



Fully vaccinated are you?
As I have unhappily found over the years, where you use a fixture to measure, it is typically for reason beyond holding it which you can use a vice for (in the case cited). I'm not saying one cannot do certain studies on the individual instruments which make up the gage - that's a given in high rel shops. The system as a whole is important, though.

In the simple situation described, you would probably get away with it because of the simpicity - but as a QS assessor I would want studies on parts in the holding fixture. As soon as you increase complexity slightly over the simple torgue example you're asking for trouble if you dont. Let's say in the torque test described you are testing to a certain 4" bolt. The fixture may have a built in height that determines how much of the shaft is exposed during the test. What I'm trying to point out is more often than not a fixture has an effect on a measurement and sometimes it's dramatic.

A good example is a spring tension test holding fixture. In cases where you have small springs (such as those which return brake shoes to their inward 'standby' position after breaking the car on the 'old' foundation {drum} brakes) if the 'hook' that goes around the spring end is rounded you will get a different reading than if it is squared off. If the spring is tested a bit off center, the reading will differ. If the 'hook' that goes through the spring end is wider (if square) or the diameter is larger (if it is round) than a hook on another 'fixture' it will read differently. In one case I was involved in, both the manufacturer and we had identical spring test machines. The only way we could get the same readings is when we shipped the holding fixture with the springs to be tested which made things interesting because the springs were made in Germany and shipped here.

I point this out only to ensure you understand that a fixture ALONE can affect the reading to such a very large degree that while you want to do certain studies on the individual instrument (or instruments) attached to, or used in conjunction with, the fixture, discounting the fixture and not doing your study with the fixture could come back to bite you.

One size does not fit all. Make sure you understand how the system as a whole functions in your specific case. Spring engineers and automatic transmission part engineers will tell you that there is seldom an acceptable alturnate to using the fixture except in very basic cases.

All this said, fixture design its self is often very important. In the case of vibration testing - back in the 1980's - I was involved in test fixture design for holding CCAs (circuit card assemblies) during vibration and thermal shock testing. The test fixtures had to be designed with their resonant frequency taken into cosideration along with the resonant frequency of the CCAs. We used magnesium for vibration fixtures because other metals do not have the damping effect (most metals tend to 'ring' like a bell) magnesium has. This is basically it (from a 1988 Mac picture):


Since we were montoring vibration characteristics and testing for effects to the CCAs themselves, the fixture was one of the most important parts of the 'system'. We even did a finite element analysis on the fixture to ensure we well understood its characteristics.

Summary: Never under estimate the importance of the effects of a test or holding fixture as a part of a system as a whole. And if you do not understand the significance of saying you are measuring something in a 'restrained' configuration (as is often done with very flexible parts), you may need to learn more about the role of fixturing in measurement and test of parts.

Just my 2 cents :thedeal:


Can't change my vote?

While this is a Poll thread, one has to explain the reason for doing so. I voted "not required". In the example of using a vise to secure a bolt for torque testing, there was no thought to where the bolt was being held. If you were simulating the test to prove that it doesn't snap when torqued, the fixture would have to be a stack up similar to actual use. I guess that makes it part of the test. I can't take back my vote.
But, if I held a bracket in a vise while torque testing a brazed clinch nut, I wouldn't say it is required to be included. Unless I had to simulate torque breakage in actual use such vertical, horizontal or upside down positioning. So, it would appear that most "holding" fixtures would have to be considered part of the process. Not having exposure to QS, are they really that finicky? Or, is this an area subject to educated opinions of the assessor? I mean, it makes sense if actual operation is being used as the standard. Do you really have to argue the non relevance of your holding fixtures that you feel are not important to this study?
:confused: :smokin:


Fully vaccinated are you?
If you haven't done the QS dance, you haven't experienced 'pickiness'. Comparatively, ISO is a walk in the part. Yup - QS auditors can be, and typically are, that 'picky'. :thedeal:

Even in production. When I worked with one client in QS, they had an automated welding process. The holding fixtures measured nothing. None the less, because of their impact on the manufacturing process (weld location) was critical (and the parts were big), every fixture had to be removed every 24 hours and literally calibrated. They were in the calibration system just as measurement gages were.

QS-9000 brings new meaning to the word 'picky'. But then again, I do admit that in this case it was a necessary, appropriate approach with consideration to the part, the process as a whole, and the end product. Tracking the process proved it was cheaper to calibrate each fixture daily than to tolerate the scrap levels without daily calibration. They had 3 complete sets of holding fixtures for that line - over 80 fixtures.


I guess it would help to give more information for my particular situation:rolleyes: I realize that in some situations the fixture may determine the outcome of the measurement being performed or the quality of product produced,I'm just not sure in my situation it does. Let me explain.We produce alot of different powdered metal products,each of which may have a separate holder used to destructive test a part.The part basicly is just supported by the holder.(Example:supports a hub,nib,flange).Parts are compression tested using a UTM. The UTM is calibrated (certified by a outside lab )and the holding fixture is calibrated. The load is applied to the part until failure.Problem#1 How do I do a part specific R&R(for PPAP)?Problem #2 How do I do a gage R&R (the holder)? Problem #3 Do I have to? We are a QS9000 company and it has not come up but I wonder if its because it hasn't been found.:) Thanks for your previous insights!:cool:


We are QS-9000 and have similar problems. If you are worried solely for PPAP reasons, the customer can waive any requirement of PPAP they like and it takes precident over the QS-9000 requirements. If your customer will accept your R&R and not require a part specific one, you won't need to address the problem.

In the instance you mention, it sounds as though the test cannot be done without a specific calibrated holder. This is just what Marc was pointing out and I agree with him - you need to include the holder in the R&R for the UTM.

The situation I was trying to point out was one in which it made no difference how the part was held. The holder would be independant of the equipment.

I assume you are doing the test in an "in-house-lab" to verify your own work, or testing incoming product for suitability. If this is the case and you are QS-9000 - YES, you would have to do a gage R&R on the equipment. In the case you describe, the R&R should include the holder with the UTM. There would be no logic in requireing a seperate R&R on the holder itself as it is intrinsic to the complete test.

That is all of course - IMHO.

Thread starter Similar threads Forum Replies Date
D Gage R&R on a Load Cell fixture that tests the resistance of a Headrest Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 5
T Simulated Use Cardiac Catheter Test Fixture Gage R&R Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 1
C Multiple Fixture Automated Vision System GR&R (Gage R&R) Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 2
M Checking a male taper using a female air gage fixture - Air Gaging question Inspection, Prints (Drawings), Testing, Sampling and Related Topics 5
K Validating a gage/fixture in-house under TS 16949 - Need information General Measurement Device and Calibration Topics 2
T Gage R&R for Checking Fixture with multiple check points Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 6
F Gage R&R Destructive Test With Breakaway Fixture To Simulate A Part Inspection, Prints (Drawings), Testing, Sampling and Related Topics 4
B Stability study- Plastic injection molded parts with fixture gage & digital indicator Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 2
gohyl Fixture Setup Design Manufacturing and Related Processes 3
A Calibration of spring loaded test fixture General Measurement Device and Calibration Topics 5
W Medical Device - fixture qualification and MSA Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 0
D Checking fixture color coding General Measurement Device and Calibration Topics 2
briteme4 Customer Requests FAI on Tooling Fixture AS9100, IAQG, NADCAP and Aerospace related Standards and Requirements 3
J Standard used to determine if check fixture gauge is acceptable Reliability Analysis - Predictions, Testing and Standards 2
R Question on determining defective units - I am not recording fixture to part rejected Statistical Analysis Tools, Techniques and SPC 5
B Design of fixture checking including Position of hole and slot General Measurement Device and Calibration Topics 5
D EMC Testing for a Production Fixture CE Marking (Conformité Européene) / CB Scheme 0
E GR&R for a test fixture that outputs variable data per measurement Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 1
B Finding a Fixture Design Course to meet Customer Requirements General Measurement Device and Calibration Topics 3
E GR&R ANOVA 3rd Factor for Fixture Nests Using Minitab Software 3
L GR&R for a Test Fixture Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 12
M Checking Fixture for Stamping Parts Manufacturing and Related Processes 2
B Cpk vs Ppk to look at the Capability by Fixture Capability, Accuracy and Stability - Processes, Machines, etc. 4
S MSA Help or guidelines - Plastics - Setting up an MSA on a multi cavity fixture Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 2
J Should failure mode caused by Fixture problem be into PFMEA? FMEA and Control Plans 2
J Definition of Tool, Fixture, Jig, etc... Inspection, Prints (Drawings), Testing, Sampling and Related Topics 8
S Calibration/Certification requirements for an Incoming Inspection Fixture Inspection, Prints (Drawings), Testing, Sampling and Related Topics 8
G Source of a Clear Fixture Block on a x-y Video Microscope - Rafaelco? Inspection, Prints (Drawings), Testing, Sampling and Related Topics 3
J Adjustable Shaft for a Test Fixture to Test Perpendicularity Inspection, Prints (Drawings), Testing, Sampling and Related Topics 5
J Check Fixture Design For Sheet Metal Part Inspection, Prints (Drawings), Testing, Sampling and Related Topics 1
Q Does this calibration method of a specific fixture make sense? General Measurement Device and Calibration Topics 7
P Check Fixture Costs - Simple check fixture (go/no go) that checks 3-4 points Inspection, Prints (Drawings), Testing, Sampling and Related Topics 4
V How to design a gauge (fixture) for measurement of distance between two hole Design and Development of Products and Processes 23
E Right Term for this Assembly - Loading Fixture Clip? Design and Development of Products and Processes 4
K CMM Coordinate Systems: Part Coordinate System vs. Fixture Coordinate System Inspection, Prints (Drawings), Testing, Sampling and Related Topics 16
J Proper way to calibrate a check fixture General Measurement Device and Calibration Topics 7
D Procedure for Fixture Gages that check True Position of holes General Measurement Device and Calibration Topics 4
Q Gage Pin Sets? Calibrate/Verify them all or just a sample size? General Measurement Device and Calibration Topics 9
S If 4 operate to measure, what is the value of k2?(MSA gage R&R) Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 1
S Faro Arm, Gage R&R Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 5
8 MSA--Should I Use Parts or Gage Pins? Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 2
C Gage Block Grade 1 - Calibration Measurement Uncertainty (MU) 15
R Gage Measuring 15 Parts at a Time Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 9
Q Gage calibration in disarray ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 12
M Gage R&R automated test equipment Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 5
PQ Systems Recipe for Success! 10 Ingredients for a Healthy Gage Management System Using GAGEpack Software 0
D Gage Repeatability for Faro Arm Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 3
S Comparing measurement results for a part from two ring gage General Measurement Device and Calibration Topics 3
M Quick Gage R&R Question Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 9
PQ Systems Best Practices In Gage Management Using GAGEpack Software 0

Similar threads

Top Bottom