I'm in the market for a decent torque wrench for my RV-8 build. I just need a wrench to get me through the tail/wings/fuse for now. I can pick up another wrench and/or borrow for the engine/prop. As far as I can figure, it should be a 1/4" and in the 20-150 inch pound range. Most of my tools that I use often are Sioux, Klein, Snap-On, Mastercraft etc, so I'm not afraid of buying quality on the tools I use often. With the amount of times I will use it, is it necessary to spend the big bucks on a good torque wrench? Is a wrench from Princess Auto being too cheap in this area? The common mid-range wrench that I read from other builders, appears to be the CDI Wrenches, which are a Snap-On brand.
What kind of click-type 1/4" wrench in the 20-150 inch pound range do you suggest?
Torque Wrench
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I_Heart_Seaplanes
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Re: Torque Wrench
I was in the market for a torque wrench for some bike work. Looked at the ones from Princess Auto and Harbour Freight. I was told by friends that had them that they were useless. The PA one sometimes never "clicked" and when compared to the calibrated ones in the tool crib, were way off. I was also told that even the expensive ones in the shop were out of spec when they arrived, just from shipping. So the chances of a low cost one being accurate are slim to nill. I figured that if I was going to spend the time torquing everything to spec, I might as well money on the right tool. I ended up borrowing one from an AME buddy.
FWIW If it was my plane, I would buy and calibrate a good one, or see if renting in more economical.
FWIW If it was my plane, I would buy and calibrate a good one, or see if renting in more economical.
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Colonel Sanders
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Re: Torque Wrench
The beam pointer lives!!!
Heh heh heh ... it can never go out of calibration!
Heh heh heh ... it can never go out of calibration!
Re: Torque Wrench
In my experience, getting an "OK" wrench then having it calibrated will yield better results than buying a more expensive one with only factory calibration.
A higher end wrench will maintain its calibration longer and wear better, but if you're not using it daily it doesn't matter.
Cheap ones are just crap and sometimes can't even be calibrated properly or consistantly.
Hed- oops, Colonel: nothing wrong with a deflecting beam wrench! Shitty for awkward angles or obstructed vis though.
A higher end wrench will maintain its calibration longer and wear better, but if you're not using it daily it doesn't matter.
Cheap ones are just crap and sometimes can't even be calibrated properly or consistantly.
Hed- oops, Colonel: nothing wrong with a deflecting beam wrench! Shitty for awkward angles or obstructed vis though.
Re: Torque Wrench
I like the beam pointer concept, Colonel, but I also like space in my tool chest. Clicker torque wrenches are big enough, let alone swinging that battle axe around! -- Some tools you are just buying the name, and something you can get away with cheapies. I was just curious if the Princess Auto/Harbor Freight ones...so far, clearly they're not to spec.
Any recommendations? What's a "good one" that you guys and gals keep referring to? Will the CDI suffice? Let me in on the secret! I've got some AN3's waiting!
Any recommendations? What's a "good one" that you guys and gals keep referring to? Will the CDI suffice? Let me in on the secret! I've got some AN3's waiting!
Re: Torque Wrench
I'll start out by saying the Snap-on/CDI torque wrenches are junk. We have lots of them and they can't make it six months without going way out of calibration. We will never buy another.
Cheap ones are hit and miss. Craftsman, Mastercraft, Husky, Princess Auto sometimes they work, sometimes they seize up. The exception is Harbor Freight. Stupidly cheap, accurate and holds calibration. Check the net for reviews. Anybody bashing them have admittedly never owned one.
If you can't get over the stigma of buying a cheap wrench, Proto is about the best out there. Accurate and we've never had to calibrate one yet. Very nice and similar priced to other premium wrenches.
Cheap ones are hit and miss. Craftsman, Mastercraft, Husky, Princess Auto sometimes they work, sometimes they seize up. The exception is Harbor Freight. Stupidly cheap, accurate and holds calibration. Check the net for reviews. Anybody bashing them have admittedly never owned one.
If you can't get over the stigma of buying a cheap wrench, Proto is about the best out there. Accurate and we've never had to calibrate one yet. Very nice and similar priced to other premium wrenches.
Re: Torque Wrench
The more I get reading, the more I wonder if +/-1 to 4% is really necessary. I am building an airplane, not a watch.
Here are some suggested torque values:
AN3 20 to 25 Inch Pounds -- Average 23 = -15/+9% Average Torque Value Tolerance
AN4 50 to 70 Inch Pounds -- Average 60 = -20/+16% Average Torque Value Tolerance
AN5 100 to 140 Inch Pounds -- Average 120 = -20/+16% Average Torque Value Tolerance
AN6 160 to 190 Inch Pounds -- Average 175 = -9/+8% Average Torque Value Tolerance
AN7 450 to 500 Inch Pounds -- Average 475 = -5/+5% Average Torque Value Tolerance
AN8 480 to 690 Inch Pounds -- Average 585 = -22/+18% Average Torque Value Tolerance
AN9 800 to 1000 Inch Pounds -- Average 900 = -13/+11% Average Torque Value Tolerance
AN10 1100 to 1300 Inch Pounds -- Average 1200 = -9/+8% Average Torque Value Tolerance
AN12 2300 to 2500 Inch Pounds -- Average 2400 = -4/+4% Average Torque Value Tolerance
The average torque value tolerances are roughly calculated and rounded. I haven't read too much into the plans beyond the tail, but my understanding is the majority of bolts on this project (tail, wings, fuse) are AN3 and AN4. These have quite a tolerance range. I am wondering if it is really neccessary to buy a wrench that is +/-1% when the tolerance range is about +/-15% for most of the work!
Obviously on critical parts (ie Prop) I will use/rent/borrow an accurate, high end, calibrated wrench. For these parts with such a large range of tolerances, I am starting to think that the Princess Auto torque wrench will suffice. Even if it seizes up, it has a lifetime warranty and I can go swap it for a new one. Heck, if I want to "re-calibrate" every so often -- I can swap it for a new one!
Here are some suggested torque values:
AN3 20 to 25 Inch Pounds -- Average 23 = -15/+9% Average Torque Value Tolerance
AN4 50 to 70 Inch Pounds -- Average 60 = -20/+16% Average Torque Value Tolerance
AN5 100 to 140 Inch Pounds -- Average 120 = -20/+16% Average Torque Value Tolerance
AN6 160 to 190 Inch Pounds -- Average 175 = -9/+8% Average Torque Value Tolerance
AN7 450 to 500 Inch Pounds -- Average 475 = -5/+5% Average Torque Value Tolerance
AN8 480 to 690 Inch Pounds -- Average 585 = -22/+18% Average Torque Value Tolerance
AN9 800 to 1000 Inch Pounds -- Average 900 = -13/+11% Average Torque Value Tolerance
AN10 1100 to 1300 Inch Pounds -- Average 1200 = -9/+8% Average Torque Value Tolerance
AN12 2300 to 2500 Inch Pounds -- Average 2400 = -4/+4% Average Torque Value Tolerance
The average torque value tolerances are roughly calculated and rounded. I haven't read too much into the plans beyond the tail, but my understanding is the majority of bolts on this project (tail, wings, fuse) are AN3 and AN4. These have quite a tolerance range. I am wondering if it is really neccessary to buy a wrench that is +/-1% when the tolerance range is about +/-15% for most of the work!
Obviously on critical parts (ie Prop) I will use/rent/borrow an accurate, high end, calibrated wrench. For these parts with such a large range of tolerances, I am starting to think that the Princess Auto torque wrench will suffice. Even if it seizes up, it has a lifetime warranty and I can go swap it for a new one. Heck, if I want to "re-calibrate" every so often -- I can swap it for a new one!
Last edited by Adam Oke on Sun Feb 19, 2012 1:35 pm, edited 1 time in total.
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Colonel Sanders
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Re: Torque Wrench
I hope you know this already:
esp on the little an3 and an4, oil on the threads can make a HUGE difference when you apply torque. Pay careful attention to the specs - I suspect they're dry torque values - and do it that way.
When you're starting out, yes, use a torque wrench everywhere. But as you get some years of experience, you will find out that you simply can't fit a bulky torque wrench into every nook and cranny of an airplane - sometimes you're lucky to fit a cut-down wrench. I won't tell you what to do in those circumstances, to avoid another attack by the legal beagles here, who live in their ivory towers.
I will mention that an experienced mechanic can torque, by feel, amazingly accurately, even if no one dares mentions it. All it takes is years of practice.
PS If you want to laugh - or cry - over some screwed-up torque values, take a peek at Cessna SEB07. The original version called for 450 to 500 inch-lbs of torque. The revised version called to replace all the bolts and nuts damaged by the above factory-specified over-torquing, and for 160 to 190 inch-lbs of torque.
Oops. Obviously it was very important, when you complied with the first version of SEB07, that you precisely over-torque to between 450 and 500 inch-lbs.
esp on the little an3 and an4, oil on the threads can make a HUGE difference when you apply torque. Pay careful attention to the specs - I suspect they're dry torque values - and do it that way.
When you're starting out, yes, use a torque wrench everywhere. But as you get some years of experience, you will find out that you simply can't fit a bulky torque wrench into every nook and cranny of an airplane - sometimes you're lucky to fit a cut-down wrench. I won't tell you what to do in those circumstances, to avoid another attack by the legal beagles here, who live in their ivory towers.
I will mention that an experienced mechanic can torque, by feel, amazingly accurately, even if no one dares mentions it. All it takes is years of practice.
PS If you want to laugh - or cry - over some screwed-up torque values, take a peek at Cessna SEB07. The original version called for 450 to 500 inch-lbs of torque. The revised version called to replace all the bolts and nuts damaged by the above factory-specified over-torquing, and for 160 to 190 inch-lbs of torque.
Oops. Obviously it was very important, when you complied with the first version of SEB07, that you precisely over-torque to between 450 and 500 inch-lbs.
Last edited by Colonel Sanders on Sun Feb 19, 2012 1:38 pm, edited 1 time in total.
Re: Torque Wrench
Thanks. Yes, those are dry values. As for accuracy with experience, I believe it. For the time being, I have only set about 100 rivets and there are 4 bolts sitting loose on a hinge bracket waiting for some inch pounds...so I will be using a torque wrench whenever I can!Colonel Sanders wrote:I hope you know this already:
esp on the little an3 and an4, oil on the threads can make a HUGE difference when you apply torque. Pay careful attention to the specs - I suspect they're dry torque values - and do it that way.
When you're starting out, yes, use a torque wrench everywhere. But as you get some years of experience, you will find out that you simply can't fit a bulky torque wrench into every nook and cranny of an airplane - sometimes you're lucky to fit a cut-down wrench. I won't tell you what to do in those circumstances, to avoid another attack by the legal beagles here, who live in their ivory towers.
I will mention that an experienced mechanic can torque, by feel, amazingly accurately, even if no one dares mentions it. All it takes is years of practice.
Oh, and I did find a long lost beam pointer, but it is 20-140 foot pounds. I also stumbled across a ~1940's Vintage Snap-On Tools Corp Dial-Type Torqometer. I have a feeling it is out of calibration, and they likely won't service that bad boy. Still looking for a wrench!
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Hornblower
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Re: Torque Wrench
I got a little 0 - 100 lb/in beam type torque wrench about 20 years ago, it was probably 30 yrs old when I got it ... senior ctizen gave it to me after he retired from the automotive trade. I didn't have one that went that low, click types don't go that low, and dial ones are really expensive. Anyways I said what the hell, and sent it out for calibration. Turns out it was spot on, not even one lb/in out al the way to 50, after about 4 yrs I stopped sending it out cause it was never off, and nothing ever changed. Still works well ... great for checking run down torques, brg preloads and running torques of asembled components and shafts. I have no problem with beam type torque wrenches. If you're going to buy a cheapie; beam type is the way to go.Colonel Sanders wrote:The beam pointer lives!!!
Heh heh heh ... it can never go out of calibration!
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Colonel Sanders
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- Joined: Sun Jun 14, 2009 5:17 pm
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Re: Torque Wrench
Beam pointers give incredible bang for the buck, even if they have no snob appeal.
Re: Torque Wrench
As a 20+ year grey haired AME, I totally agree that the old school beam type are the best and most accurate for your home tool box were you do not need to pay for the expensive calibration of the click type torque wrench. I did a quick Ebay search and there was a 0-60 in-lbs 1/4" and a 0-200 in-lbs and then a 0-600 in-lbs in 3/8.
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Fling Wing
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Re: Torque Wrench
Princess auto, got a 0-140 ft/lb beam type for $6 (bargain bin), used one all through highschool shop, and now use this one for changing my tires over on the civic. Dad laughed, but it beats $50 for a canadian tire digital wrench.
On a more serious note, in AME school we used snap-on 1/4 drives 90% of the time, really nice and small in my opinion, but cost around $300 I think. When those were all taken, we got a proto I think it was, I kinda liked it better, when it reached torque it really let you know it.
On a more serious note, in AME school we used snap-on 1/4 drives 90% of the time, really nice and small in my opinion, but cost around $300 I think. When those were all taken, we got a proto I think it was, I kinda liked it better, when it reached torque it really let you know it.
Re: Torque Wrench
Had a 20-200 inch pound 1/4" Prinny Auto Special, used it for two years on automotive/heavy duty.
For shits got it calibrated with the other stuff for the new job...
For 50 in-lbs set 49.
Can't argue with that. Just didn't loosen it past 20, clicked it every once a while with a low torque in my hand and kept it in a case. Maybe used it 4-5 times a month.
Think it was 29.99 a couple years ago. I still get in trouble for not buying it on sale.
For shits got it calibrated with the other stuff for the new job...
For 50 in-lbs set 49.
Can't argue with that. Just didn't loosen it past 20, clicked it every once a while with a low torque in my hand and kept it in a case. Maybe used it 4-5 times a month.
Think it was 29.99 a couple years ago. I still get in trouble for not buying it on sale.
Re: Torque Wrench
Where can one calibrate a wrench? Is it standard for most shops to have a comparator mounted on the wall?
I'd buy a cheapie if I knew I could walk into a wrencher's shop at the end of the day for a quick check...with a beer in hand of course.
I'd buy a cheapie if I knew I could walk into a wrencher's shop at the end of the day for a quick check...with a beer in hand of course.
Re: Torque Wrench
Another thing you all should know, as it may well be relevant here; There is no regulatory requirement to calibrate your torque wrench or any other precision instrument, unless, the manufacturer of the aeronautical product makes a specification as to the accuracy required.
Also, in most cases there is no need to send these things out to 'certified' shops for recalibration. "national standard" (all lower-case, important distinction in the world of government..), is the term used.
A foot-pound, an inch-pound and newton-meter are all national standards. So is an inch of water-column, a PSI or an inch of mercury; all stuff you could rig up in your shop for the purposes of calibrating your tools.
CAR 571.02
(2) A person who performs maintenance or elementary work pursuant to subsection (1) shall ensure that any measuring device or test equipment used
(a) meets the specifications of the manufacturer of the aeronautical product with respect to accuracy, taking into account the intended use; and
(b) if calibration requirements are published by the manufacturer of the measuring device or test equipment, is calibrated by means traceable to a national standard.
(amended 2003/06/01; previous version)
Most people don't know that.
C.A.
Also, in most cases there is no need to send these things out to 'certified' shops for recalibration. "national standard" (all lower-case, important distinction in the world of government..), is the term used.
A foot-pound, an inch-pound and newton-meter are all national standards. So is an inch of water-column, a PSI or an inch of mercury; all stuff you could rig up in your shop for the purposes of calibrating your tools.
CAR 571.02
(2) A person who performs maintenance or elementary work pursuant to subsection (1) shall ensure that any measuring device or test equipment used
(a) meets the specifications of the manufacturer of the aeronautical product with respect to accuracy, taking into account the intended use; and
(b) if calibration requirements are published by the manufacturer of the measuring device or test equipment, is calibrated by means traceable to a national standard.
(amended 2003/06/01; previous version)
Most people don't know that.
C.A.
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lost in the north
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Re: Torque Wrench
Can anyone direct me to the car that requires torque wrenches to be calibrated yearly?
Re: Torque Wrench
For those who want to calibrate you own torque wrenches.
And much more.
http://www.rcramer.com/shop/torq_cal.shtml
http://www.boltscience.com/pages/tighten.htm
http://www.myturbodiesel.com/1000q/torq ... ch-FAQ.htm
http://home.jtan.com/~joe/KIAT/kiat_3.htm
Bob
And much more.
http://www.rcramer.com/shop/torq_cal.shtml
http://www.boltscience.com/pages/tighten.htm
http://www.myturbodiesel.com/1000q/torq ... ch-FAQ.htm
http://home.jtan.com/~joe/KIAT/kiat_3.htm
Bob
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ChallengerDan
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Re: Torque Wrench
lost in the north wrote:Can anyone direct me to the car that requires torque wrenches to be calibrated yearly?
Maintenance and Elementary Work Performance Rules
(amended 2000/12/01; previous version)
571.02 (1) Subject to subsection (2), a person who performs maintenance or elementary work on an aeronautical product shall use the most recent methods, techniques, practices, parts, materials, tools, equipment and test apparatuses that are:
(...)
(2) A person who performs maintenance or elementary work pursuant to subsection (1) shall ensure that any measuring device or test equipment used
(a) meets the specifications of the manufacturer of the aeronautical product with respect to accuracy, taking into account the intended use; and
(b) if calibration requirements are published by the manufacturer of the measuring device or test equipment, is calibrated by means traceable to a national standard.
(amended 2003/06/01; previous version)
From the snap-on web site on one of their TW:
Warning Must Read Instructions Mandatory Eye Protection Mandatory
WARNING
Do not exceed rated torque.
Do not use to break fasteners loose.
Periodic recalibration is needed to maintain accuracy.
Jetco calibration tools recommends 6 months to a year, but says that actual reliability will be dependent upon use. http://www.itorque.com/Cal%20Interval.pdf
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ChallengerDan
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Re: Torque Wrench
When taken into the context of an AMO, here is what TC says:
"...the maintenance policy manual (MPM) of a domestic AMO Certificate holder shall contain at least the following information...
(x) Procedures to control the calibration of tools and equipment as required by CAR 571.02."
CAR 571.02 requires that the appropriate tools are used and that measuring and test equipment be accurate and calibrated.
As this area is important, consider what a tool is used for, how often it is used, and how it is stored and handled. After reading CAR 571.02, draw up a calibration schedule. Keep in mind that sending out all tools for calibration once a year may not be necessary. A tool used only a couple times yearly for a single task will probably not need recalibrating every year, while a tool used daily for many tasks may need calibration every few months. Minimum calibration intervals may be specified by the manufacturer.
Example:
All measuring devices and test equipment will:
Meet any requirements published by the manufacturer of the measuring device with respect to accuracy.
Meet any calibration requirements that are published by the tool manufacturer.
Be inspected before use.
Any tool suspected of inaccuracy or damage, despite meeting any other requirements, will be taken out of service, repaired and calibrated, or replaced.
Where calibration is required, be calibrated in accordance with a national standard.
Each precision tool will have a calibration sticker attached. Records relating to the calibration of the tool will be retained on file.
http://www.tc.gc.ca/eng/civilaviation/p ... 4-3133.htm
"...the maintenance policy manual (MPM) of a domestic AMO Certificate holder shall contain at least the following information...
(x) Procedures to control the calibration of tools and equipment as required by CAR 571.02."
CAR 571.02 requires that the appropriate tools are used and that measuring and test equipment be accurate and calibrated.
As this area is important, consider what a tool is used for, how often it is used, and how it is stored and handled. After reading CAR 571.02, draw up a calibration schedule. Keep in mind that sending out all tools for calibration once a year may not be necessary. A tool used only a couple times yearly for a single task will probably not need recalibrating every year, while a tool used daily for many tasks may need calibration every few months. Minimum calibration intervals may be specified by the manufacturer.
Example:
All measuring devices and test equipment will:
Meet any requirements published by the manufacturer of the measuring device with respect to accuracy.
Meet any calibration requirements that are published by the tool manufacturer.
Be inspected before use.
Any tool suspected of inaccuracy or damage, despite meeting any other requirements, will be taken out of service, repaired and calibrated, or replaced.
Where calibration is required, be calibrated in accordance with a national standard.
Each precision tool will have a calibration sticker attached. Records relating to the calibration of the tool will be retained on file.
http://www.tc.gc.ca/eng/civilaviation/p ... 4-3133.htm
