Who says you can't calibrate a steel rule!

Elsmar Forum Sponsor

Wes Bucey

Prophet of Profit
Channeling Clinton:
It depends on what your definition of "calibrate" is.
mark (a gauge or instrument) with a standard scale of readings.

  • correlate the readings of (an instrument) with those of a standard in order to check the instrument's accuracy.

  • adjust (experimental results) to take external factors into account or to allow comparison with other data.

Does ALL calibration require adjustment? Or can "some" calibration merely be a process of affirming or denying whether the instrument is within its stated tolerances? Perhaps something as simple as saying this is no longer meeting one tolerance class, but may meet a lesser class of tolerances. Here's an example of thread tolerances to get an idea that a gage, for instance, "could" gradually move down in class as it wears.
Tolerance classes

A classification system exists for ease of manufacture and interchangeability of fabricated threaded items. Most (but certainly not all) threaded items are made to a classification standard called the Unified Screw Thread Standard Series. This system is analogous to the fits used with assembled parts.
Classes 1A, 2A, 3A apply to external threads; Classes 1B, 2B, 3B apply to internal threads.
Class 1 threads are loosely fitting threads intended for ease of assembly or use in a dirty environment.
Class 2 threads are the most common. They are designed to maximize strength considering typical machine shop capability and machine practice.
Class 3 threads are used for closer tolerances.
Thread class refers to the acceptable range of pitch diameter for any given thread. The pitch diameter is indicated as Dp in the figure shown above. There are several methods that are used to measure the pitch diameter. The most common method used in production is by way of a Go/no go gauge.


Stop X-bar/R Madness!!
Trusted Information Resource
My definition of calibrate is very simple: Verify a measurement system against a standard to assure its accuracy.

Adjustment is not calibration, only an option to react to an out of calibration condition. If you can adjust, fine - do so. If not, pitch it or "reclassify" it.

Gotta love definitions. When its all said and done, they are not very definitive.


Involved In Discussions
I think advocating for not calibrating really misses the critical point on what that calibration is buying you. It is providing book-ends in the measurements made between those calibration points, and thus the acceptance and rejection decisions, were accurate. I'm always scheptical of when organizations buy a new, calibrated gage and then rather than get it calibrated, they dispose of it and buy a new one. I understand that is often cheaper (ex. Set of pin gages) but there isn't any closure on the gages.

I don't think the thread is about advocating for/against calibration. It's more a case of whether a steel rule SHOULD be calibrated compared to simply being verified. Knowing how far "off" a steel rule is, for most uses isn't really necessary and it's likely not the right tool, if you do need to know.

Steve Prevette

Deming Disciple
Super Moderator
In my past life with a calibration program, we would have referred to the test on the steel rule as a "calibration check".

Generally, if a steel rule were to fail its cal check, the only remedy is to dispose of it and buy a new one, I would suppose, unless there were a special case like I could sand some off the end . . .


Fully vaccinated are you?
You can calibrate gauge blocks. You just have to have the right tools. :D
Yeah, but only if the block has "grown" which will not help because wear is usually the problem to begin with. Of course one could make a "new" smaller gage block.

With regard to the thread topic this is along the lines of "calibration" of a glass bulb thermometer. There is nothing to "adjust".


The on line dictionary defines calibration as:

1: to ascertain the caliber of
2: to determine, rectify, or mark the graduations of
3: to standardize by determining the deviation from a standard so as to
ascertain the proper correction factors
4: to adjust precisely for a particular function
5: to measure precisely; especially : to measure against a standard

I guess number 1,3 & 5 could apply. Number 2 & 4 might be a stretch for a steel ruler.


Stop X-bar/R Madness!!
Trusted Information Resource
I would rather calibrate a steel rule than try to "calibrate" this gage block... The only thing to wring is the neck of the guy who stored it wet.

Nobody ever said calibration had to be difficult...all you need is a gage and a standard (helps to have a controlled environment, but sounds like some folks don't even want to go there....) Standards at 10:1 or 4:1, depending on whose theories you subscribe to. If the gage matches the standard, you "win" - congrats! Champagne for everyone!


Last edited:
Thread starter Similar threads Forum Replies Date
Marc GM says no more tailpipe emissions by 2035, carbon neutrality by 2040 World News 46
T What does AS9100 mean when it says you must establish a process to do X? AS9100, IAQG, NADCAP and Aerospace related Standards and Requirements 24
Marc NASA Says Oregon Company Metals Fraud Caused $700 Million Satellite Failure - 2019 World News 16
B Our NB says that IEC 62304 is an ISO 14971 Requirement ISO 14971 - Medical Device Risk Management 1
shimonv 21 CFR 820.20(d) says: Each manufacturer shall establish a Quality Plan 21 CFR Part 820 - US FDA Quality System Regulations (QSR) 4
J jwmuola says Hello Coffee Break and Water Cooler Discussions 1
Marc FCC boss says he'll SHAME broadband firms for fibbing on speeds After Work and Weekend Discussion Topics 0
J Auditor says 5.6.3 should be discussed in Management Review Management Review Meetings and related Processes 62
Wes Bucey "Back Doors" to Encryption - NY times says NSA has them After Work and Weekend Discussion Topics 20
Wes Bucey A Headhunter says he has job hunt secrets Career and Occupation Discussions 7
O Is it an Assignable Cause only if the Control Chart says so? Statistical Analysis Tools, Techniques and SPC 16
S Auditor says a Minor Nonconformance will become a Major Nonconformance General Auditing Discussions 8
H 'You've got to find what you love,' Jobs says Career and Occupation Discussions 2
Marc Threat analyst says medical devices can be hacked remotely Other Medical Device and Orthopedic Related Topics 6
Jen Kirley What do you do when an auditee says "No thank you" Internal Auditing 86
P Control of Monitoring and Measurement Devices - ISO 13485 Clause 7.6 says ... ISO 13485:2016 - Medical Device Quality Management Systems 3
J Quality Pros? Salaries on the Upswing, ASQ Salary Survey Says Career and Occupation Discussions 4
Stijloor IKEA US Says Thank You to All Its 12,400 Co-Workers World News 5
D Found Watch - Watch is "Element" and says "New York" Coffee Break and Water Cooler Discussions 16
G Dangerous Act - Auditor says major nonconformance for safety (risk) issue Occupational Health & Safety Management Standards 21
C Calibration Laboratory Location - GMP says in a secure bonded area General Measurement Device and Calibration Topics 5
Stijloor Ford Says It Made $2.7 Billion in 2009 World News 8
E FMEA Action Plan Threshold (RPN) - Auditor says Action Plan for an RPN > 84 IATF 16949 - Automotive Quality Systems Standard 21
J Modern man a wimp says anthropologist Coffee Break and Water Cooler Discussions 0
bobdoering Wheeler is back again! He says it is the last volley! Statistical Analysis Tools, Techniques and SPC 7
J Immortality only 20 years away says scientist Coffee Break and Water Cooler Discussions 20
P Attribute Control Chart in my Process - Black Belt says Not Appropriate Quality Tools, Improvement and Analysis 11
J Using 3 Basics to find Position - Customer says to use the X, Y and Z Basics Inspection, Prints (Drawings), Testing, Sampling and Related Topics 16
Marc SANS Report Says Organizations Focusing On the Wrong Security Threats After Work and Weekend Discussion Topics 0
bobdoering Toyota forecasts $8.6B loss, says 1 million sales will vanish World News 2
M The FDA says device regulation will move toward harmonization... 21 CFR Part 820 - US FDA Quality System Regulations (QSR) 6
Marc Anonymous Caller? New Service Says, Not Any More World News 2
J Standards for loyalty barcodes - USA says that C128 is their standard Other ISO and International Standards and European Regulations 6
tony s Auditor says our Quality Manual is deficient. What can you say? Quality Management System (QMS) Manuals 58
J Print says "Reference Only" - NOT - Thread call out for a 3/8-32 UNEF-2A Nonconformance and Corrective Action 7
Stijloor What Your Boss Says and What He Really Means Coffee Break and Water Cooler Discussions 3
Marc US Internet Backbones Could Max Out before 2010, Study Says After Work and Weekend Discussion Topics 3
Stijloor Toyota is Slipping, Consumer Reports Says Coffee Break and Water Cooler Discussions 12
Stijloor Drunken astronauts allowed to fly, panel says Coffee Break and Water Cooler Discussions 17
E MSA Manual says the sum of EV,AV,GRR, and PV cannot equal 100%? Why? Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 2
J Sales Force (Catalogue) says We are TS16949 Certified - Is this allowed? IATF 16949 - Automotive Quality Systems Standard 2
J Einstein says... Coffee Break and Water Cooler Discussions 5
Marc Oil Company CEO Pay Averaged $32.7 Million in 2005, Study Says World News 2
Crusader Process Approach beef - Registrar says that we 'should' use the process approach General Auditing Discussions 20
B Preferred methodology for internal audits - CEO says we're spending too much time Internal Auditing 8
T DaimlerChrysler says it will cut 6,000 administrative jobs over three years World News 2
P Gage R&R - What does the % tolerance says about my Gage Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 1
Marc Lawsuit says Delphi faked sales to improve financial reports World News 0
D What the AIAG manual says about the frequency of MSA - Measurement system analysis Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 11
Marc U.K., Germany, France Competitiveness and Efficiency Slips, WEF Says World News 0

Similar threads

Top Bottom