Torque Wrenches, calibration, accuracy.

Please do not use a torque wrench if you do not understand how it works, what it does, and where/how to check the calibration, accuracy.

torque wrench (http://www.answers.com/topic/torque-wrench-2)

Up Tight With Torque Wrenches by Charlie Zarek (http://www.geocities.com/motorcity/downs/3837/torqwren.html)

JLW Instruments (http://www.jlwinstruments.com/torque-tips.htm)

webBikeWorld (http://www.webbikeworld.com/r3/torque-wrench/)

webBikeWorld page #2. (http://www.webbikeworld.com/r3/torque-wrench/dial-torque-wrench.htm)


Have a great day.

Thanks whunter. Those are good short explanations. One question I have always had is about thread lubrication. As one of the links mentioned, the lubrication of the thread affects the final torque reading a lot. However it is almost never specified in any manual I have seen. It just lists the torque.

Mike

That's why I got one of these bad boys. It does inch pounds, foot pounds and newton meters at the push of a button. Still needs calibration checked once every 5 years or so but it's damn accurate otherwise.
http://buy1.snapon.com/catalog/item.asp?item_ID=68414&group_ID=17509

Thanks whunter. Those are good short explanations. One question I have always had is about thread lubrication. As one of the links mentioned, the lubrication of the thread affects the final torque reading a lot. However it is almost never specified in any manual I have seen. It just lists the torque.

Mike
Torque / Tension Control: General Data

http://pweb.jps.net/~snowbum Torque values for various fasteners on the various models of airheads (http://pweb.jps.net/~snowbum/torquevalues.htm)

What is Torque?
http://www.google.com/search?q=What+is+Torque%3F+&rls=com.microsoft:en-us&ie=UTF-8&oe=UTF-8&startIndex=&startPage=1

Dynamic Coatings, Inc. (http://www.dynamiccoatingsinc.com/torqueTension.htm)

Perfect Engine Sealing Starts With Proper Head Bolt Use by Larry Carley (http://www.aa1car.com/library/2005/eb70536.htm)

Torque Modifiers: Waxes, Lubes and Specialty Chemicals By Thomas S. Doppke
Technical Presentations Co. Sterling Heights, Michigan (http://www.pfonline.com/articles/059907.html)

Fasteners: Talking Torque
Too loose, and your fastener can vibrate or work free. Too tight, and your fastener can snap. Distributors that explain torque, and can measure it, help their customers avoid possible disaster
By Thomas Doppke, President, Technical Presentations Co.
Industrial Distribution March 1, 2004 (http://www.manufacturing.net/ind/article/CA385719.html?pubdate=3%2F1%2F2004)

Barrett Engineering Consulting (http://www.tcnj.edu/~rgraham/barrett/manual1-A.html)

Bolted joints and screw threads - fatigue of bolts/studs, fatigue/stresses in pinned joints, strength of bolts, load distribution in joints, torque/tension relation, locking. (http://aerade.cranfield.ac.uk/cgi-bin/search.pl?caseful=off&stemming=on&ranking=on&referrals=on&view=default&maxserver=8&method=any&boolean=and&attrib2=ANY&templatetype=ALL&term2=Bolted+joints+and+screw+threads)

Torque Chart based on the use of clean, dry threads. (http://www.morbark.com/Service/belttorque.pdf)

Good stuff. I have Harbor fright torque wrenches and I compared my 1/2" to a neighbors, and they were within 5% of the low and high end of each other. Either they are both totally wrong or they are pretty close. I do know that it is important to store the click types "loose".

Sears sells a torque wrench tester, but it's $1000, I think - I like tools, but I can't justify it (maybe a larger club could?). And of course, even that has to be calibrated eventually. Wish I still worked at a company with a factory - we had an entire metrology department that had EVERYTHING, and I mean, everything - and it was all traceable to NIST standards.

BTW, that Snap-on unit is of interesting construction. The old-fashioned "beam" torque wrenches were IMHO more rugged but also a pain to use because of their width and the gauge reading problems. Just guessing here, but this must use some kind of a miniature electronic load cell internally.

When the patent expires, it'll be at Sears for $99.95, and Harbor Frieght for $39.99...but I probably won't be doing this stuff by then!

http://www.imperialinc.com/pdf/A_FastenerTorqueCharts.pdf

http://www.boltdepot.com/fastener-information/Bolts/Metric-Recommended-Torque.aspx

http://www.imperialinc.com/pdf/A_FastenerTorqueCharts.pdf

http://www.boltdepot.com/fastener-information/Bolts/Metric-Recommended-Torque.aspx

http://mdmetric.com/tech/torqcht1.htm

http://books.google.com/books?id=vKLxdXxVavYC&pg=PT328&lpg=PT328&dq=metric+bolt+torque+chart&source=web&ots=96j_mNp5Wc&sig=Z0IWqTSncOMFynKiyQ-ZgBkP7yw#PPT326,M1

http://colorado4wheel.com/manuals/Jeep/WJ/1999_WJ_FSM_Interactive(Including%20Diesel)/ewj_in.pdf

http://www.mechanicsupport.com/TellMeMore1.html

http://www.boltdepot.com/fastener-information/Bolts/





http://www.intermotive.net/Tech%20Tip/Tech%20Tip%20-%20Jan%2008.pdf

http://www.geocities.com/dtmcbride/home_garden/bolts.html

http://www.stanleyproto.com/default.asp?TYPE=STATICLEFT&PAGE=ConversionsCharts.htm&LEFT=left_ConversionsCharts.htm

http://mdmetric.com/techindex.htm

http://www.bossard.com/techinfo/en/doc/Index1-0.htm

http://www.stanleyproto.com/default.asp?TYPE=STATICLEFT&PAGE=ConversionsCharts.htm&LEFT=left_ConversionsCharts.htm