To the OP,
Here are a couple other points.
There's some relevant info in this post and thread:
http://www.garagejournal.com/forum/showpost.php?p=3151707&postcount=25
You need to focus on
how you're pulling on the wrench as part of this. You also need to make sure the adapter is secure. How are you setting up the adapter for your checks?
I have found that letting off right as the wrench is starting to click will give readings consistently under the torque you're trying to achieve.
Also, I think you need to adjust the setting on the adapter. Don't set the adapter for a certain torque setting and then try to use that to check your wrenches. That's really not the best way to do it.
Set the adapter so it just displays the torque input, not so it's waiting to achieve a certain torque and beep. Then, check the adapter reading when the torque wrench clicks. I think you'll find that is a better way to check torque wrenches. And again, you need to think about your pulling method on the wrench.
There are so many variables in torquing something, such as the accuracy and consistency of the wrench, how you pull on the wrench, whether the threads are lubricated, etc. Just because a torque wrench says "+ or - 4%" doesn't mean you'll get that consistently in the real world or even when you're checking it with a torque adapter.
Learning more about how to pull on the wrench -and adjusting it up and down and exercising it before use- have given me much more accurate and consistent results.
