To Verify Concentricity of Flats to a Centerline

Douglas E. Purdy

Quite Involved in Discussions
#1
For my edification, how is one to verify concentricity of flats to a centerline (ex: .001 T.I.R.) on a drill? In my readings so far it would appear that I would use a fixture with a V-Block and a dial indicator. But I do not know how to do it. Would someone tell me how to do it? There is not much of a surface to rotate on between the fluted body and the flattened portion of the shank (and the tool does have back taper - if that matters). I am including a portion of the drawing with most of the dimensions missing.

I am being told that the accepted practice is to take a micrometer and measure the distance between the flats and the opposite circumference/perimeter and see that they are within .001. Does this method of measurement verify the concentricity requirement? My gut says no, so I am asking for confirmation as well.

Thanks,
Doug
 

Attachments

Elsmar Forum Sponsor

Jim Wynne

Staff member
Admin
#2
Douglas E. Purdy said:
For my edification, how is one to verify concentricity of flats to a centerline (ex: .001 T.I.R.) on a drill?
Concentricity doesn't involve a "TIR" measurement (at least not a conventional TIR measurement); you're thinking of runout.

Douglas E. Purdy said:
In my readings so far it would appear that I would use a fixture with a V-Block and a dial indicator. But I do not know how to do it. Would someone tell me how to do it? There is not much of a surface to rotate on between the fluted body and the flattened portion of the shank (and the tool does have back taper - if that matters). I am including a portion of the drawing with most of the dimensions missing.
Is "concentricity" actually called out? This seems like more of a position application.

Douglas E. Purdy said:
I am being told that the accepted practice is to take a micrometer and measure the distance between the flats and the opposite circumference/perimeter and see that they are within .001. Does this method of measurement verify the concentricity requirement? My gut says no, so I am asking for confirmation as well.
Your gut is correct; the method you describe would give a good approximation of true position, not concentricity. Have a look at this thread, especially the post where Pilchard gives a good description of the GD&T definition of concentricity.
 
J
#3
More on C'line

JSW is right about the other thread. There is a lot of good underlying information there, but after looking at your drawing I think I would have to go with the Micrometer method. Don't get em wrong, there may be better, more accurate ways to check this But......

Regardless of what the GDT callout is, The question must be what is the purpose of the flats and what is critical about them? My assumption would be that the drill is to be held in a 3 jaw chuck and that runout on the drill is to be avoided. Therefore the flats must be equally positioned around the shank, and not tapered away from the c'line. Since I assume that you purchase the drill and add the flats, we can assume that the shank as received is concentric to the tip of the drill. Therefore measuring with a mic. at 2 or 3 points form the flat to the opposite side will tell you if the flats are correct is size, and taper. Any taper encountered could be extrapolated over the length of the drill to determine how much runout might be found in application.

I have concerns about the use of a V-Block and indicator. The reason is the fact that you have little or no shaft to rotate around, only the flutes of the drill. (I am assuming this is a 2 flute drill.)

To do this right you would need a way to clamp the drill in a rotating head. Preferably one with degree graduations on it. Then, using an indicator on a stand run the indicator tip over the flat, fine tuning the rotation of the head until you have as flat a reading as possible. Then Rotate the head 120 degrees and check again. This will also tell you how accurate the flats are in the 120 degree dim. This will be a slow process.

Another way around the flute problem would be to have a cylinder made up bored to the precise drill size. The drill could then be inserted and mouned on the V block. This is dangerous though, since any variation in the cylinder can through off the readings on the flats.

All in all I would have to go with the micrometer method as the fastest simplest and most reliable.

Hope this helps
 

Douglas E. Purdy

Quite Involved in Discussions
#4
JSW05 said:
Concentricity doesn't involve a "TIR" measurement (at least not a conventional TIR measurement); you're thinking of runout.

Is "concentricity" actually called out? This seems like more of a position application..
You tell me, the drawing has a note that states:"FLATS CONCENTRIC TO CENTERLINE WITHIN .001 T.I.R."

JSW05 said:
Your gut is correct; the method you describe would give a good approximation of true position, not concentricity. Have a look at this thread, especially the post where Pilchard gives a good description of the GD&T definition of concentricity.
JSW05,

I have been reading the thread with interest. I even asked about the 200 years experience with parts and drawings. But was not able to synthesize all the information back and forth between the experts. That is why I thought I would present my situation - to see if the experts could help me.

Thanks,
Doug
 

Jim Wynne

Staff member
Admin
#5
Douglas E. Purdy said:
You tell me, the drawing has a note that states:"FLATS CONCENTRIC TO CENTERLINE WITHIN .001 T.I.R."
You need to ask the customer what's expected. Do they mean "concentric" in its common sense of "coaxial," or "sharing a centerline," (which would actually be postion or runout in GD&T parlance)or do they mean that they're looking for the GD&T variety of concentricity? The fact that "T.I.R." is explicitly called out makes it seem like position or runout is what's required.

Douglas E. Purdy said:
JSW05,

I have been reading the thread with interest. I even asked about the 200 years experience with parts and drawings. But was not able to synthesize all the information back and forth between the experts. That is why I thought I would present my situation - to see if the experts could help me.
Whenever there's confusion over a specification, the designer or customer authority is the only source that can be sure about what was intended. It's best to review drawings at the quotation stage and make sure that ambiguities are cleared up, of course. Any answers you get here will just be guesses.
 

Douglas E. Purdy

Quite Involved in Discussions
#6
JRKH said:
JSW is right about the other thread. There is a lot of good underlying information there, but after looking at your drawing I think I would have to go with the Micrometer method. Don't get em wrong, there may be better, more accurate ways to check this But......

Regardless of what the GDT callout is, The question must be what is the purpose of the flats and what is critical about them? My assumption would be that the drill is to be held in a 3 jaw chuck and that runout on the drill is to be avoided. Therefore the flats must be equally positioned around the shank, and not tapered away from the c'line. Since I assume that you purchase the drill and add the flats, we can assume that the shank as received is concentric to the tip of the drill. Therefore measuring with a mic. at 2 or 3 points form the flat to the opposite side will tell you if the flats are correct is size, and taper. Any taper encountered could be extrapolated over the length of the drill to determine how much runout might be found in application.
JRKH,

Your assumptions are right on (above and below), except for the drills being purchased. The company I am working with makes metal cutting tools. I am trying to learn the business. Run-Out is checked prior to the flats being machined, but apparently the TIR requirement of the flats are not being checked. I am looking into this issue to see what we can do to verify the requirement.

Doug

JRKH said:
I have concerns about the use of a V-Block and indicator. The reason is the fact that you have little or no shaft to rotate around, only the flutes of the drill. (I am assuming this is a 2 flute drill.)

To do this right you would need a way to clamp the drill in a rotating head. Preferably one with degree graduations on it. Then, using an indicator on a stand run the indicator tip over the flat, fine tuning the rotation of the head until you have as flat a reading as possible. Then Rotate the head 120 degrees and check again. This will also tell you how accurate the flats are in the 120 degree dim. This will be a slow process.
JRKH

We verify the 120 Degrees requirement on a goniometer (vision system). But this doesn't help me with the TIR - does it? Or am I missing something?

Doug

JRKH said:
Another way around the flute problem would be to have a cylinder made up bored to the precise drill size. The drill could then be inserted and mouned on the V block. This is dangerous though, since any variation in the cylinder can through off the readings on the flats.

All in all I would have to go with the micrometer method as the fastest simplest and most reliable.

Hope this helps
JRKH,

I appreciate all the help. The particular customer on some other tools does require that the Run-Out be verified simulating the drilling action by having a gage built so the tools are rotated and R/O checked at a given distance from the gage. But this is not promoted/required with these tools.

Thanks,
Doug
 
B

bmccabe - 2006

#7
I second JSW. Talk to the customer, 'cause concentricity and flats are dissimilar units. Divide overflow.
 
J
#8
You seem to have it well on...

Douglas E. Purdy said:
JRKH,
JRKH

We verify the 120 Degrees requirement on a goniometer (vision system). But this doesn't help me with the TIR - does it? Or am I missing something?

I appreciate all the help. The particular customer on some other tools does require that the Run-Out be verified simulating the drilling action by having a gage built so the tools are rotated and R/O checked at a given distance from the gage. But this is not promoted/required with these tools.

Thanks,
Doug
I'm not familiar with the goniometer so cannot comment on its usefulness in this case, but it sounds as if you have sufficient equipment to find the answer. I guess at this point I would have to agree with the others to check with the customer. Although I suspect that what you're going to find that what he wants is for the drill to run straight when he installs it in his machine, regardless of how he called it out.
Best of luck.
Just curious, have there been complaints that may be traced to this feature?

James
 

Jim Wynne

Staff member
Admin
#9
JRKH said:
I suspect that what you're going to find that what he wants is for the drill to run straight when he installs it in his machine, regardless of how he called it out.
James
That's certainly where the smart money should be. I think more people need to get into the habit of questioning ambiguous specifications, though, and when the customer offers clarification, get it in writing.
 

Hershal

Metrologist-Auditor
Staff member
Super Moderator
#10
OK Folks.....I am going to show that I am NOT the world's leading expert here......:bonk:

The drawing suggests a somewhat normal drill bit and the measurement in question at the connection end.....

If I am correct, why are we concerned about the connection, aside from its influence as a Type B contributor?

Hershal
 
Thread starter Similar threads Forum Replies Date
qualprod D5 of 8D clarification, how to verify root cause Problem Solving, Root Cause Fault and Failure Analysis 24
C Where to draw the line for "sufficient evidence" to verify safety/performance of a device? CE Marking (Conformité Européene) / CB Scheme 2
K Verify Software Architecture - supporting interfaces between items IEC 62304 - Medical Device Software Life Cycle Processes 2
M How to verify profile gages provided by customer General Measurement Device and Calibration Topics 5
E Layouts : Can you "verify" things that are not visible (such as loctite present, internal dimensions) in a layout ? APQP and PPAP 2
K How to verify the Storage and Transport environmental condition for Medical Device Miscellaneous Environmental Standards and EMS Related Discussions 3
J How to verify the actual capacity of suppliers Supplier Quality Assurance and other Supplier Issues 3
V Regrinding Material - Verify whether a product contains any regrinding material Manufacturing and Related Processes 13
Q Using Caliper A to verify Caliper B - Verification of Calibration ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 5
V Tie-wrap pull test to verify contact retention Manufacturing and Related Processes 6
D How to Calibrate and Verify a Heating Oven General Measurement Device and Calibration Topics 3
A How to Verify Supplier I-9 Forms for ITAR Requirements Other ISO and International Standards and European Regulations 2
O Creating a Tool to Track & Verify Mistake Proofing Devices Document Control Systems, Procedures, Forms and Templates 5
N What is the easiest way to verify we have the correct customer supplied materials? Misc. Quality Assurance and Business Systems Related Topics 5
R IEC 62304 - 5.2.9 Verify Software Requirement IEC 62304 - Medical Device Software Life Cycle Processes 5
B Verify GB/T 16886 is the same as ISO 10993 US Food and Drug Administration (FDA) 5
A How to verify and validate the effectiveness of CAPA with regards to employees ? 21 CFR Part 820 - US FDA Quality System Regulations (QSR) 5
R IEC 62304 Section 5.3.6 Verify Software Architecture IEC 62304 - Medical Device Software Life Cycle Processes 4
R LKV Value: Can not verify Reliasoft Case Study Reliability Analysis - Predictions, Testing and Standards 2
S Verify Software System Testing: Verify that results meet the Pass/Fail Criteria IEC 62304 - Medical Device Software Life Cycle Processes 1
L Gauge to test and verify a Set Square Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 1
D What to verify on Test Setup for Environmental Testing General Measurement Device and Calibration Topics 7
A When to verify and when to validate Design Changes 21 CFR Part 820 - US FDA Quality System Regulations (QSR) 4
D Since NIST # can not be used to verify Traceability - What an Auditor should do AS9100, IAQG, NADCAP and Aerospace related Standards and Requirements 8
C I need to verify the surface profile of a part - Sine plates General Measurement Device and Calibration Topics 4
W How to verify/calibrate a Neptune Water Meter General Measurement Device and Calibration Topics 4
optomist1 CMM Shortcomings - GD&T - Inability of CMMs to verify the MMC situation Inspection, Prints (Drawings), Testing, Sampling and Related Topics 4
C How to Calibrate and Verify Torque Multiplier Gages General Measurement Device and Calibration Topics 6
J How do I continually Verify Compliance to my Processes? ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 3
R A way to verify 7075 T0 Aluminum has been successfully Heat Treated to T6 Inspection, Prints (Drawings), Testing, Sampling and Related Topics 6
Ron Rompen Recommended Rockwell 30T Scale Hardness Tester to verify Incoming Product General Measurement Device and Calibration Topics 1
D How to verify a process that uses software to accomplish certain tasks? ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 1
X Cannot Verify until Customer uses Product - Clause 7.5.2 ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 7
C Surface Plate Calibration - How to verify the flatness of a granite surface plate General Measurement Device and Calibration Topics 1
E How Do You VERIFY Customer Property? ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 13
R Verify Accuracy for Validation of CNC Starrett Vision System Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 1
L Verify, Inc. Source Inspection experience? Inspection, Prints (Drawings), Testing, Sampling and Related Topics 1
H Definition Inspect, Review, Verify and Witness - What are the definitions and differences? Definitions, Acronyms, Abbreviations and Interpretations Listed Alphabetically 5
B How to inspect Mylars to verify dimensions, grid lines and grid points Inspection, Prints (Drawings), Testing, Sampling and Related Topics 17
D How do I verify the Cold Room temperature in Restaurant Kitchen Food Safety - ISO 22000, HACCP (21 CFR 120) 7
C Bridgeport Mill as a Gage - Verify gage dimensions using a Bridgeport Mill Measurement Uncertainty (MU) 4
A Test Method - DIN ISO 1133 for melt flow needed to verify supplier results Manufacturing and Related Processes 1
F How would you Verify Repeatability and Reproducibility of Measurement Systems? Quality Tools, Improvement and Analysis 5
S How to Calibrate or Verify Screw Pitch Gages General Measurement Device and Calibration Topics 16
J Work Instruction to Calibrate or Verify a Combination Square General Measurement Device and Calibration Topics 15
H Hygrometer Calibration - Best way to verify accuracy of a 'reference' Hygrometer? General Measurement Device and Calibration Topics 11
C How to verify the SAL (sterilie acceptable level) is 10-6 for ETO Sterilization ISO 13485:2016 - Medical Device Quality Management Systems 6
K Could someone verify the levels of quality management system standards Misc. Quality Assurance and Business Systems Related Topics 2
K Prohibited metal verification - I am not sure of a PHYSICAL way to verify this Various Other Specifications, Standards, and related Requirements 9
P CMM Programming verification - How would you verify that a CMM program is correct? Quality Tools, Improvement and Analysis 5

Similar threads

Top Bottom