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Thread: Torque Wrench

  1. #21
    Quote Originally Posted by SLG View Post
    Fishing,

    It is my understanding from Borka...
    Thx

    I may give them a call - I would like to understand this better,and do make stuff that looks pretty cool.

    I get the operating principle of it their torque tool - but it still seems like there are camming surfaces as well as a spring involved to provide the "snap" once the torque setting is reached -these would be sources of variation as well as wear, which IMO would necessitate calibration or verification.

  2. #22
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    Jan 2017
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    Farminton Hills, MI
    Quote Originally Posted by fishing View Post
    SLG -

    Could you help me understand the latter part a bit more fully?

    I have not handled the Borka, but I did just do a little reading/viewing on it.

    Having a bit of experience with metrology but am not an expert - I do not understand how that tool "doesn't need calibration".

    I do understand the principle of it's operation, and it seems like the internal components would be liable to producing drift or variance through wear/use over time.






    More broadly per the thread - I use and have been happy with the FAT wrench for all my amateur gunsmithing/building needs

    • Repeatability is more important to me than outright accuracy for the majority of fastener torquing i do while tinkering on my guns.
    • The FAT wrench I have performs adequately for me, and I have tested it on a mid-level torque tester tool out of curiousity.
    • The majority of fasteners I torque on guns are torqued within the middle sweet spot of the FAT wrenches 10-65 in/lb range.
    • I return the tool to minimum torque after every use.
    • If spending the money to get a FAT wrench or whatever other torque tool - I think it is important to get a high quality set of bits as well if not already owned.





    I'm not really concerned that the fasteners on this mount may be 10% off from the desired torque setting for example as the mount and fasteners are strong enough to take it, but I do want to make sure they are consistently 10% off in the same direction so that stresses/pressure are even across the optic - the FAT wrench works for me in this regard.


    About calibration - please see my previous post, #10, from Kortik. Except for production line torque tools, which see tens of thousands of cycles, and may indeed wear in a relatively short period of time, periodic calibration of hand driven tools is more of a matter of paperwork in order to pass annual company audits than anything else. Even tools that were NOT used at all are required to have a fresh calibration sticker, good at at least for a year, otherwise, it becomes a matter of non-compliance with audit requirements. Anybody who works or worked in QS compliant company of related nature is likely to know that. Tools of individual users are not, thank God, subjects of QS audits, which is a good thing.

    Specifically in regard to Borka torque driver (ATD or MTD). It uses preset force of the spring compression, which is not adjustable by the user. Spring is permanently compressed to approximately 45% of its allowable load, and stays like this 99.9999% of the time. Spring is a high quality item, custom made for Borka Tools in the U.S., and was designed with support and direct input from the Rockford Spring (IL) design specialist. All work stresses for this spring are way below yield stress for the material of the wire, and spring is never compressed to the solid height or close to the solid height, which may result in a spring set (change of spring specs). Spring, which is permanently loaded at 45% and occasionally cycles between 45% and 60% is expected to relax, over estimated 30-35 years, or more than 50,000 cycles, but this relaxation is estimated, by general spring design knowledge, to not exceed 5% (5% loss of spring rate = 5% loss of preset force=5% loss of preset torque). Realistically, no gun owner is going to be able to apply 50,000 cycles at all, more like 500-1500 cycles at a most, which provides a huge safety margin by itself. Also, we preset our torque drivers at +2% relative to nominal, so even if torque driver limiting torque is down 5% in 30 years, it will still be within tolerance of +/-4%. We run endurance cycle test for ATD(MTD) torque drivers (2 units), both passed 40,000 cycles with an average of 2.8% drop in limiting torque settings, and stayed in tolerance.

    The logic behind "no calibration required" is that it is a hand driven tool with relatively low stress compression of the quality made spring, which is expected to see limited number of cycles, and which has tuned design, supported by the endurance test, general engineering knowledge and "prior art" in spring design.

    Hope my reply is satisfactory, but if you have any questions, please feel free to ask.

    Boris
    Borka Tools
    Last edited by kortik; 01-22-2017 at 04:49 PM.

  3. #23
    Quote Originally Posted by kortik View Post
    About calibration...
    thanks boris - didnt realize you were on the forum but its great that you are active.

    10-4 on the calibration - I understand the paperwork driven nature of much of the requirements for ISO/trade compliance etc etc, and of course I agree with ya that the critical-ity as well usage of these tools for gun tinkering is nowhere near that of industries such as vehicle assembly, medical equipment etc.

    My responses previously were based on the claim made of "no calibration required" which seemed dubious, but genuinely piqued my curiosity.

  4. #24
    Member
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    Jan 2017
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    Farminton Hills, MI
    Quote Originally Posted by fishing View Post
    thanks boris - didnt realize you were on the forum but its great that you are active.

    10-4 on the calibration - I understand the paperwork driven nature of much of the requirements for ISO/trade compliance etc etc, and of course I agree with ya that the critical-ity as well usage of these tools for gun tinkering is nowhere near that of industries such as vehicle assembly, medical equipment etc.

    My responses previously were based on the claim made of "no calibration required" which seemed dubious, but genuinely piqued my curiosity.
    You're very welcome. It was my second post on PF, I'm a very new member here. Actually, I was encouraged by this web site owner, Mr. Tom Jones, to present myself and do not hide behind the screen name, and I've appreciated his advice very much. This website seems like a great place to share whatever related technical knowledge all of us may have, and discuss pure technical details without getting emotional...

    If you have any questions or concerns, please call 248-798-7621 or e-mail to info@borkatools.com
    Last edited by kortik; 01-22-2017 at 05:05 PM.

  5. #25
    Just to reiterate, since the man himself is here and we don't see that very often...

    I have 3 personal sets of Borka tools. I also have one issued set from work. They are all awesome, and for anyone who appreciates high quality, well thought out tools, at what I would consider very reasonable prices for the value, get a Borka. You won't regret it.

    BTW, I don't know Boris personally, and he doesn't know me. We spoke on the phone the first time I was considering a set, and he was very helpful. As I said before, my friends in the scope industry also think very highly of his stuff. I'm a shooter, not a gun plumber, and tools that are easy to use and effective are what I want.

  6. #26
    Member
    Join Date
    Jan 2017
    Location
    Farminton Hills, MI
    Quote Originally Posted by SLG View Post
    Just to reiterate, since the man himself is here and we don't see that very often...

    I have 3 personal sets of Borka tools. I also have one issued set from work. They are all awesome, and for anyone who appreciates high quality, well thought out tools, at what I would consider very reasonable prices for the value, get a Borka. You won't regret it.

    BTW, I don't know Boris personally, and he doesn't know me. We spoke on the phone the first time I was considering a set, and he was very helpful. As I said before, my friends in the scope industry also think very highly of his stuff. I'm a shooter, not a gun plumber, and tools that are easy to use and effective are what I want.
    I certainly very much appreciate your kind words and unsolicited positive feedback. Being a small company, we at Borka Tools do value such things a lot, and truly like to hear and talk to our customers, which is a way for us to make sure we're doing something right or something needs to be changed. As a side effect of being a small company, we can change or, if necessary, correct things real fast, which, I think, is a positive. Thanks a lot, SLG.

  7. #27
    You're very welcome, I hope you stick around. I'm sure plenty of people here would benefit from your info.

  8. #28
    Notorious Derp Merchant
    Join Date
    Nov 2011
    Location
    Brooklyn NY
    Quote Originally Posted by kortik View Post
    Hope my reply is satisfactory, but if you have any questions, please feel free to ask.

    Boris
    Borka Tools
    Pistol-forum, where all the experts live. . . .

    Thanks Boris! Very interesting reply.

  9. #29
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    Feb 2011
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    Off Camber
    Quote Originally Posted by 5pins View Post
    A guy that use to work here bought some Facom torque drivers. They are around $270 each. They are in Newton meters so you have to convert it over to inch pounds to use it. I think I used it once.

    Attachment 13244
    Interesting. That looks a lot like my SK Torque Screwdriver.

    Last edited by JV_; 01-22-2017 at 07:50 PM.

  10. #30
    Member
    Join Date
    Jan 2017
    Location
    Phoenix Arizona
    I have been using Sturtevant torque wrenches, and torque screwdrivers for ages. I used to find the Sturtevant screwdrivers brand new, with blemished dial windows that can be polished back out with paper and jeweler's rouge. The Sturtevant is supposed to be stored at 4 inch pounds, and the other one is a dial type, so it has no adjustments. I just bought a new old stock Mossberg wrench, and really like it a lot. My other inch pound wrenches are Bonney Uticas, that have always been stored drive side up set at 2 inch pounds or with no tension on the springs. Whatever the manufacturer says is correct. I have my stuff calibrated every year or two, or at least have one wrench calibrated and use it to calibrate the other with, which is iffy, but it usually works. Now I have a torquometer that is a calibration device, and allows me to just have it calibrated every 6 months, and can charge other shops to check their equipment.

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