Toroue Wrench ... calibration and metric measurements

[Kabota]

I am going to rebuild my recently acquired L 1801DT. Got some good advice from ya all in this thread I started...

http://www.orangetractortalks.com/forums/showthread.php?t=39122&page=3

In this thread Jim L. mentioned on post #27 that I should be sure to use a recently calibrated torque wrench. I am not a mechanic and my diy neighbors never talk about calibrating their torque wrenches.

So should I have it professionally calibrated ? or is it ok to use diy methods demonstrated on youtube videos?

If I buy a new torque wrench do I need to worry about calibration?

Since Kubota specifications are given in metric units.... should I buy a metric torque wrench or just mathematically convert.

I have worked with metric specs before and I just use math and convert to English so I can use my measuring tools.

I do have a digital read out caliper that reads out both metric and English.... but otherwise I am old school manually reading calipers and micrometers.

So was wondering what precision measuring tools you use when rebuilding a metric engine ?

 

[Jim L.]

So should I have it professionally calibrated ? or is it ok to use diy methods demonstrated on youtube videos?

Suggest that you look at harbor freight quinn 1/2" drive digital torque adapter. Something like this will let you calibrate or work in place of a torque wrench.

If I buy a new torque wrench do I need to worry about calibration?

Yes, even new.

Since Kubota specifications are given in metric units.... should I buy a metric torque wrench or just mathematically convert.

No need to purchase special equipment, just convert and write it down.

Stuff that goes to the machine shop will get precision work. Tractors are supposed to be designed to be maintained with standard hand tools.

When you plan to put in the head gasket, there is a lot of bad information on the internet. What and how the old gasket comes off, cleanliness, and tools for soft aluminum come to mind. Start another thread on that to get better workshop standards.

 

[Creature Meadow]

I am a Metrologist for the company I work for and have been doing calibration for 20 years.

I calibrate a lot of torque wrenches and yes you can do the math and convert english to metric.

The common torque wrench I cal has a 6% accuracy some more expensive ones are in the 2 to 3% range.

I have inch pound and foot pound torque wrenches. The inch pounds are from 0-75 while my foot pounds are 0-100 and one 0-600.

I use a rule of thumb of 10% to 90% of the range to work in, kind of the sweet zone.

I have a drawer full of wrenches at work that are out of tolerance, exceeds the mfr's stated permissible limits.

I have found that Snap On wrenches are the most reliable that I have cal'd and Utica are nice as well. Armstrong made a nice wrench but no knowledge with newer ones.

I would go with a dial version so no worries when you go to use it that the battery is dead.

Not sure I helped you any but good luck.

 

[NoJacketRequired]

You can also do some rough calibration of your torque wrenches yourself. Find some fixed weights and have them weighed on a calibrated scale (post office works well for this!). Clamp the drive end of the wrench in a vise. Use a loop or rope or similar to hang your weights from the handle end of the torque wrench. Measure accurately the distance from the centre of the drive end to the point where you will hang your weights. Now you can adjust your click-style or dial-gauge torque wrench based on your test weights.

I've got a 20lb and 50lb weight that I use for this purpose, allowing me 20, 50 and 70 lb-ft calibration points. My cheapo made-in-China 1/2" drive torque wrench is pretty good, just barely making the 6% allowance. My DeWalt 3/8" drive torque wrench goes from about 2% to about 10% across its scale. Thankfully I normally only use it in the first third of its range where it's still holding better than 5%.