Not logged inAmerican Welding Society Forum
Forum AWS Website Help Search Login
Up Topic Welding Industry / General Welding Discussion / AISC Fabricators - A Survey
- - By drewp29 (**) Date 07-07-2020 15:49
This is a specific question for fabricators/erectors who hold an AISC certification. The type of cert does not matter - building, bridge, erector, etc.

Please give a short run-down of your method for calibrating tape measures (either Quality Control Inspectors or shop employees responsible for layouts, fit-up, setting final dimensions on assemblies).

Also, please provide the average length of the tapes calibrated and maximum lengths of fabricated assemblies in the shop.

So, as follows:

Method:

Average length of tape measure:

Max length of shop assemblies:

Hopefully I will get a few answers. I will wait until there are at least a couple responses before I explain why I am asking this.

Thanks!
Parent - By Jim Hughes (***) Date 07-07-2020 16:25
We get one from Home Depot and then get one from Lowes and compare against a 6" rule that we get from Starrett. Just kidding. Couldn't help myself.  Looking forward to reading more about this though.
Parent - - By Steelslinger (**) Date 07-07-2020 18:53
Pull tapes against the Calibrated Master Tape (certified by Calibration company every 5 years), verifying at 1ft, 5ft, 10ft, within an 1/8". QC/Final Sign-off tapes only. QC and shop Tapes are only 25' and of the same manufacturer. A sample of each batch of shop tapes are checked upon receipt from vendor.

Also verify/'calibrate' our Leica Disto Laser measuring device same way.

Longest structure built in a single stretch is 280' (building is only 300'), average is 150'.
Parent - By drewp29 (**) Date 07-07-2020 22:41
Thank you for your response!
Parent - - By drewp29 (**) Date 07-08-2020 17:13
Anyone else?
Parent - - By welderbrent (*****) Date 07-09-2020 02:07
Good Day Drew,

I am NOT an AISC approved fabricator or erector but have some thoughts here that we have in our company policy. 

We are a small inspections agency in mid AZ.  Before we shifted into full time inspections, we had a family, plus a few employees, welding fabrication shop though not AISC.  We did establish a QC program that included some guidelines we still use for the inspections business. 

For tapes, we use a 4 ft certified straight edge attached to the wall of the tool/parts room.  For the majority of industry standards, checking the first 4 ft is the critical portion and the rest falls into industry standards that are established for the manufacturers of the measuring devices. 

We also have a 25 ft certified tape that we use to verify longer tapes.  It is important to realize that the 'clip' end is where the majority of issues generally arises.  Tapes can be mandated to be replaced at certain time limits and/or when dropped to assure no damage effecting the measuring accuracy. 

It is also worth mentioning that temperature is a contributing factor.  The thin material of a tape will change faster than the steel being measured.  How about the difference between steel, stainless, cloth, and other materials that tapes are made of?  Did that cloth tape get wet?  Then the sun came out and dried it out?  How accurate is it now? 

I know AISC approved shops with some good programs for verifying tape accuracy and replacing those that...don't measure up. 

Not sure what you were looking for but hope this is worthwhile.

Have a Great Day,  Brent
Parent - By drewp29 (**) Date 07-23-2020 21:57
Thanks for the insight Brent!
Parent - By jwright650 (*****) Date 07-13-2020 19:12
I found it meaningless and a lot of unnecessary work to verify all of the tapelines used in the shop. The previous QC before me would gather up ALL of the tape lines and squares and work on them for about a week verifying. When it was my turn, I only verified the inspectors tapes and squares as they are the ones used for final inspections.

I had a 100' stainless tape that had calibration papers and a pull handle. I verified all of the tapes 12', 25', 50' and 100' etc. against that tapeline. I stretched out the calibrated tapeline and tensioned it with the pull handle for the appropriate tension for the temperature(see your calibration paperwork for the temp/tension that your tape was calibrated at). All along the floor where the tapeline was supported for it's length, I had applied tape to the floor at intervals and marked it at 1', 10', 25', 50' etc... Then pulled all of the inspector's tapes to see how they aligned against the calibrated tape marks. I called it good if the tape was within 1/8" at 50'. The Lufkin tapes were generally dead on, the Craftsman 50' tapes were off by an 1/8" at 50', but the 100' tapes were dead on.

I used the 3,4,5 rule to verify squares against a calibrated tape.
Parent - By drewp29 (**) Date 07-23-2020 23:23
Alright, so here is why I am asking.

We are an AISC certified Fabricator, and have been for 10 years now. I have been the QA/QC Manager the entire time. We have been ISO certified as well for the past ~20 years, and we have a supplemental NQA-1 Manual that is audited during our yearly ISO Audit. I was hired in 2007, and rewrote our entire quality manual to comply with the ISO 9001:2008 standard. At the time we were also IAS certified, and our manual doubled as the IAS manual (at least our Quality Control Procedures and Work Instructions). In 2010 we had an upcoming project that was requiring AISC certification, and several others we were bidding that had the requirement as well. So, we went through the initial AISC cert process. AISC became the primary requirement for projects, so in 2015 we let our IAS cert lapse. We still hold the ISO, NQA-1, and AISC certs.

All the above is really just to point out that for approximately 5 years I was dealing with 4 audits a year, which is now reduced to 3 a year. So I am no stranger to the 3rd party audit process, having had a total of 44 audits thus far. The amount of NCR/CARs we have received I can almost count on 1 hand. There have been 7 total - 3 of which were calibration related.

Going back to Al's comment regarding Fillet Gauges - yep, 2 NCRs were regarding calibration of fillet gauges. One was issued because we weren't calibrating (or rather, verifying) the CWI gauges. So I purchased a NIST traceable gauge set from GAL and started comparing the CWI's GAL gauges to the GAL Master Set every 6 months. The Master set sits in my office, and is ONLY used to verify the CWI set. So I had no plans on re-verifying the Master Set, and I wrote it into the manual as such. Apparently that wasn't good enough, because we all know Stainless Steel randomly changes shape over time (/s), right?!! So I was issued another NCR for not checking the Master Set at established intervals. Now, not only do I have to verify the CWI set, but I also have to use our NIST traceable Starrett Steel Rule (that gets sent out every 5 years) to check the Master Fillet Gauge Set once a year. This is getting ridiculous.

I almost changed my procedure to verifying the CWI set with the Starrett Steel Rule, but it is quite a bit easier to just throw the same fillet gauge up against the Master set and verify that it is exactly the same. The CWI set has been used to measure likely more than a million welds, and it is spot on the same as the Master Set.

Which leads me to the 3rd calibration related NCR/CAR. If you are AISC certified, I highly urge you to pay attention to what I am about to type.

My procedure for checking tapes was this: I have a 2 foot Starrett Steel Rule that is NIST traceable and is checked by a calibration lab every 5 years. We have a list of employees that have dimensional responsibilities. The QCI tapes are serialized by inscribing a number on the tape housing. These are the employees responsible for final dimensional checks. The other employees on the list are shop leads that measure during fabrication.

I use the Steel Rule to verify the first 2 feet of the tapes. I check the end plate for proper play, using push and pull technique, and to ensure it is still straight. I inspect the tape for cracks, bends, and verify that all the lines in the first 2 feet can be read without issue. The first few feet of the tapes is arguably the MAIN reason for inaccuracy. Acceptable accuracy is +/-1/16". We fabricate heavy steel, and super tight tolerances are not required for the product. FWIW, I have never really failed a tape. I have suggested to employees that they replace the tape soon, mostly due to dirt and grime. I have also had end plates straightened while I wait, but not even due to the accuracy being outside the 1/16" tolerance, just because I'd rather see a perfectly straight end plate. Almost every tape I have ever checked is no more than 1/64th off from every single line in the first 2 feet.

I have been verifying tapes every 3 months for the last 13 years. My procedure has been totally acceptable for all audits, including AISC, but is apparently NOT acceptable anymore.

The AISC auditor this year actually issued a CAR for this. A CAR!!! Nope, not an NCR, which is a minor non-conformance - an actual MAJOR non-conformance. What they are saying is that my procedure for checking tape measures is SO unsatisfactory that it risks our AISC certification entirely! Bull-Puckey!

According to the auditor, at least for the QCI tapes, we must be verifying the ENTIRE LENGTH of the tape. I asked where this was established as a requirement, and he pointed to section 1.14.c of the AISC 207-16 standard which states:

The documented procedure shall include provisions for:

(c) Service use for each piece of equipment, including the required precision for the types of inspections, measurements or tests made.

Tell me how exactly that equates to checking the entire length of QCI tapes? It doesn't.

So I probed further. According to the auditor (who had only been an AISC auditor for approximately 9 months), there was a presentation given at the 2018 steel conference by someone I've never heard of, and is not an official voice of AISC, about equipment calibration. They talked about all different kinds of calibration, including tape measures. They stated that checking the entire tape is advisable. Remember, this is NOT AISC saying this, this is simply a presenter at a conference.

This is the only place where one might determine that the expectation is to check the entire tape measure. AISC has never issued a bulletin regarding tape measure calibration, nor do they specifically state it as such in any AISC publication anywhere. I at least skim every AISC bulletin I receive via e-mail, even though 9/10 are not Building Standard related.

So I asked how exactly I was supposed to randomly watch a video available on the AISC website, and deem it rule of law for calibration requirements? My calibration procedure has been totally acceptable for 9 years of AISC certification, why would I consider it incorrect at this point in the game?

Ooooooooooh, now we're getting somewhere. AISC sent their auditors an e-mail approximately 3 months ago. In this e-mail, it was stated: Make sure they are checking the entire length of tape measures. The auditor could not send me the e-mail, because Super Secret Info, for auditor eyes only.

What it really boils down to is AISC moving the goal posts without notifying their fabricators of the increased stringency of requirements. If this is going to be required, they should have the expectations clearly defined somewhere in an official AISC document - not in some random Steel Conference video.

I just couldn't believe a CAR was issued. That's just ludicrous.
- - By 803056 (*****) Date 07-09-2020 16:29 Edited 07-09-2020 20:56
I sometimes wonder if we aren't over thinking the need to calibrate everything. Measuring tapes being one of the many items that fall into this class. In Europe they have different classes to indicate the measuring tape's degree of precision. I haven't found a similar system here in the US.

I would say that if the tape is purchased from a recognized manufacturer, it's "good enough". Considering the tolerances permitted by AISC for fabricated steel and the length of most structural members, a standard tape in good condition is probably good enough. None of the measuring tapes I found from several recognized manufactures include anything regarding the precision of their tapes in the range of 10 to 30 feet. Jim's comment of comparing two tapes purchased from two different big box stores, not bad for most construction.

When taping long members such as those typical of bridge construction, the biggest error introduced is more than likely due to taking the measurement while the tape is unsupported or varying the tension applied while taking the measurement.

For those that are insistent on calibration of all their measuring tapes, here's a link for the methodology from NIST.
https://www.nist.gov/system/files/documents/2017/04/28/SOP12_20141022.pdf

Next, calibrated fillet weld gages. "Are you frigging serious?"

Good luck.

Al
Parent - - By Steelslinger (**) Date 07-10-2020 16:46
Al, I have had one auditor say as much, regarding fillet weld gauges. Says that they can be damaged or worn when people use them as scapers and such. I had to laugh and said then those shops need to train their employees better on 'proper tool for the job' philosophy.

In some of our audits for AISC and local DOTs, they have specified that ALL measuring devices should be 'calibrated' yearly.

Currently, I only calibrate/verify devices that are used for Final Acceptance and a check sample of new tapes when we get them in. I do not calibrate my QC weld gauges, as they do not see any wear that would render them inaccurate.

All the dimensional errors that I've had to write up NCRs/Corrective Actions for is usually a 'hold over' error (holding on the 1 inch mark but thought it was on 1 foot mark) or misread the print, but has never been for out of calibration measuring device.

Maintaining calibration of every measuring device (i.e. tapes, squares, transits, levels, fillet weld gauges) used in the shop only causes more paperwork, and the practice of pencil whipping.
Parent - By 803056 (*****) Date 07-10-2020 17:45
If a welder is using a fillet weld gage as a scraper that welder is more ambitious than ninety percent of the welder's I've ever worked with. I would have to see someone try to use a fillet gage as a scrapper to believe it. They are too small to have a good enough grip to scrape anything more than some smut.

Most structural welding shops are not working to the nearest 0.001-inch, not even 0.01-inch. Working to the nearest 1/16-inch considered precision work in the structural steel industry.

If the shop is fabricating small components for the automobile or aerospace industry, yes, I can see the need for more precise tolerances, but not for structural steel framing. Give me a break. Have most of the AISC and DOT auditors ever actually looked at the tolerances of the steel manual for structural steel members? It is difficult to believe they have.

Al
Parent - By drewp29 (**) Date 07-23-2020 23:37
That's almost verbatim what I was told regarding the CWI Fillet Gauges. That over time, the wear from measuring would change them, and that they could have been used to chip slag off welds prior to measuring.

It's as ridiculous as it sounds. If the CWI needs a weld cleaned, they grab a laborer and have them clean the weld. In worst case scenario, you find a random piece of metal (a drop or fitup dog), and have at it. No self-respecting CWI is going to chip slag with their Fillet Gauge!
Parent - - By Jim Hughes (***) Date 07-14-2020 15:56
Good response Al. My comment from my earlier post was more of a smart-aleck comment than a recommendation. Although a Starrett 6" rule would be a pretty good calibration gauge.   :smile:
We built skids for GE a few years back and they required us to have calibrated tape measures. Yeah! I know! skids. I think our tolerance on the drawing was, as long as it was in the correct building tack it. Just kidding.  That is the only time that I can remember it was ever required and I have worked Nuclear back in 2007 and it was not required.
Parent - By 803056 (*****) Date 07-14-2020 16:26
We're on the same page with regards to calibration. There are times and applications where it is needed and others where it really is ridiculous.

My brother is a tool and die maker. He works with tolerances in millionths of an inch. Dimensions are read using optics. It is the nature of the beast and it’s the nature of the parts they manufacture.

He was helping me build a trailer to pull behind the tractor on the farm. He was measuring the thickness of the material with his micrometer and laying out with his machinist tools. He wanted a granite surface plate to work off of. I told him he was wasting his time, plus or minus a 1/16th is more than good enough for what we’re building. The concrete floor was our surface plate. He refused to help after that.

Al
Parent - By drewp29 (**) Date 07-23-2020 21:58 Edited 07-23-2020 23:26
Al - As always, your advice is very much appreciated. I think you are spot on with what you are saying. I have a longer post in which I will expand on this to reply to everyone.

Edit: That post is above - I replied to my initial comment.
- - By LToca85 (**) Date 07-21-2020 12:00
Am I the only one still wondering why the OP posted this? He said he would explain after a few responses
Parent - By Tommyjoking (****) Date 07-21-2020 21:27
AISC and more so ISO.  Want a calibrated rule and a standard written practice for "calibrating" tape measures etc in your QMS.  Basically an overpriced NIST certified rule and have it checked by a metrology lab every year.  Hang it in the shop let the operators check it and sign off on a sheet every week or have QC verify all of them once a month.  Keep a log and it makes them happy.  My logs kept track of how many were removed from service each time kinda proving we were checking basically.   I agree with previous posts....the only ones that really count are the QC ones for finals.  But if Jo Bobs tape or square is wonky ....Jo Bob may cost you some some rework.  Having a reference for operators in the shop and making it a standard practice to check regularly costs little and can save much. 

I have always had a fight with the ISO guys over calibrating every single thing in the shop....hence the "for reference only" sticker.:lol:
Parent - - By drewp29 (**) Date 07-23-2020 21:59
Sorry, I took a few days vacation after posting this and am getting back to being caught up now, so I thought I better come check if anyone else had responded.

Apologies for it taking so long!
Parent - - By SWN1158 (***) Date 07-28-2020 11:20 Edited 07-28-2020 11:26
In the October 2005 issue of the AISC monthly publication "Modern Steel Construction" in the "Documented Procedures Make Projects Better" article, there's a sample calibration procedure that states... 

"The actual gages/measuring equipment used at ABC for final acceptance of product are identified by a sticker with a serial number and calibration due date. The QC Manager maintains a log of each of these gages/measuring equipment and their calibration due dates as applicable. If any gages/measuring equipment is found without a valid identification, the gages/measuring equipment is considered a gage for in-process or reference only checks."

The AISC 207-16 Audit Guide, under 1.14 Calibration of Inspection, Measuring, states that "A documented procedure shall be developed to calibrate and maintain inspection, measuring and testing equipment."

One could easily interpret that this title implies "all" tapes, but I've always calibrated "final acceptance" tools only... squares, tapes, fillet gage, and DFT gage, and it's never been an issue.

And in my humble opinion, the calibration of the fillet weld gage used in "final acceptance" is an absolute waste of time.
Parent - By drewp29 (**) Date 07-30-2020 22:35
The vast majority of my calibration/verification are final acceptance tools only as well.

My procedure and tolerances are clearly outlined in our calibration work instruction. The problem I had with the current situation was that our procedure was not deficient, as there is no 'absolute' requirement for how to verify tape measures. Our procedure worked for us, as evidenced by the relative lack of dimensional issues we have. When we have dimensional issues, it is usually caught in process as there are parts that do not fit where they should. If everything fit together correctly, you can be relatively confident that the dimensions are fine. There are certain dims that have to be set and might not interact with other pieces, but these dimensions are verified a half dozen or more times throughout the fab process. By final inspection the piece has undergone full dimensional checks several times over by various employees.

Which is why I do check the shop tapes, or at least the employees that measure for fitup. I don't serialize those tapes though, just the QCI tapes. I include those other tapes in my calibration log because I want employees thinking about the condition of their tape and they are more likely to replace a worn tape because I am out checking every 3 months.

I'm writing my full length verification as an initial verification check only, just to verify the manufacturer did not have an issue. Beyond the initial verification I will continue checking with the steel rule every 3 months. The way I see it, as long as the full length looks good at the initial check, the steel rule will ensure that remains the case if the end plate has issues over time. The lines on the tape aren't going to magically move over time (don't say that about steel rule though, they still want that stainless plate sent out and verified). Replacement tapes will be checked upon purchase.

I am designing a caveat in that might warrant rechecking a QCI tape. Say you are checking a 35 foot tape, and everything is within the +/- 1/16" tolerance, with the worst being at the 35 foot mark, which is out 1/32". If the quarterly checks reveal the tape is off by more than 1/32" at every mark when compared to the steel rule, it stands to reason that the 35 foot mark may now be out more than 1/16". So I am going to record any hash mark that is out more than 1/32" during the initial check. That way I hopefully won't get nailed with the 'compounding errors' argument that might make an auditor force you into verifying the full length at a set interval. I won't go any finer than 1/32". At that point you are splitting hairs in our industry.
Up Topic Welding Industry / General Welding Discussion / AISC Fabricators - A Survey

Powered by mwForum 2.29.2 © 1999-2013 Markus Wichitill