I bouught an inexpensive torque wrench from Harbor Freight to do my first build. I read the instructions and set the wrench at a 10 pound setting to see how it works. The wrench won't release when I push very hard against it. Am I doing something wrong? Was it a mistake buying a inexpensive torque wrench? Thank you.

Quoted: Was it a mistake buying a inexpensive torque wrench?

Yes, for two reasons.

1. Never buy cheap tools. Cheap tools are just that, cheap. Most of the time they will provide you with more frustration than anything.

2. I don't care what the military manual says, you don't need a torque wrench to build an AR!

Return that POS, follow these instructions and you will save yourself time, money and aggravation.

Good luck!

Quoted: 2. I don't care what the military manual says, you don't need a torque wrench to build an AR!

+1 X 10 to the bazillionth power.

Throw the cheap ass torque wrench away, and never get near an AR with another one.  It's that simple.  

Besides what the others said, you may be using the wrench wrong.  The wrenches I have used, and I have used many different types on the job, do not release, they "click" at the weight setting, but if you want to keep going you can. Why you would want to do that I don't know but they do not release.
If you are expecting the wrench to release torque at the desired setting if it is like any I have used it isn't going to happen.  

Cheap clicker torque wrenches are the devil.  There may be good clickers, but I'm not dropping $300 on a torque wrench.  The cheap ones lose calibration quickly and only tell you "yes or no" on whether you've reached the target torque.  Beam types are pretty cheap, they don't lose calibration quickly, and they don't leave you in suspense about how close you are to the target torque.

I got a cheap clicker that I've had for years to torque lug nuts and stuff in the garage.  I also have a relatively expensive dial torque wrench.  I can adapt the two together and the dial and clicker track pretty closely, even now after about ten years of infrequent use.

Quoted: I got a cheap clicker that I've had for years to torque lug nuts and stuff in the garage.  I also have a relatively expensive dial torque wrench.  I can adapt the two together and the dial and clicker track pretty closely, even now after about ten years of infrequent use.

I've owned two cheap clickers (big ft-lb and little in-lb), and they both often fail to click at the right torque (based on coupling with my beam wrench).  The internal bearing surfaces are too rough, and they just get stuck.  This has caused me to strip holes in scope bases with the in-lb and engine heads with the ft-lb.  

What I'll do is chuck up the clicker, preset and adapt the dial to it.  My clicker, can't remember the brand right now, will break pretty consistently and very near the dial indication, meaning if I set the clicker for 90, the dial shows very near 90 when the clicker "clicks".  Hardly scientific, but it shows that both of these indicate pretty close and it shows my clicker is working to some degree.

Maybe I got a good, cheap clicker.

I snapped an fuel injector retainer bolt off in the head of my Volkswagen TDI with a Craftsman clicker torque wrench.  Fortunately, I was able to get the shank out easily with a screw puller and did not damage the head.  I traded it for a beam-style torque wrench.

OTOH, one of the few "cheap" tools I own is a beam-style microtorque wrench which I use for action screws on my CZ-452 where IMO consistency is as important as absolute accuracy and the accuracy is "good enough."  The CZ is pillar and glass bedded now, though, so the wrench may not be necessary for that anymore.  I also use it for scope mount and ring screws.

Since I had the beam-style Craftsman torque wrench I used it on my first build.

rmz, I have the exact same torque wrench that you have. It works great for AR-15 builds, as they only require 30# torque. The specs on this wrench say accuracy is + or - 4%. At 30#, this is only 1.2#.

Now, on the other hand, I wouldn't do precision work such as engine rebuilding with it. But for an AR-15, it the best deal for the money out there.

Now for your problem. Did it "click" then get stuck? Can you change the torque settings and try it again at a higher setting?

I took another run at this thing trying some different settings, and I now have it figured out. Bottom line- it was my lack of understanding and not the wrench. Also, excellent "insider information" about not using the wrench at all. What book or video is going to suggest that! Thanks for your replies.

Quoted: I took another run at this thing trying some different settings, and I now have it figured out. Bottom line- it was my lack of understanding and not the wrench. Also, excellent "insider information" about not using the wrench at all. What book or video is going to suggest that! Thanks for your replies.

The only thing the torque wrench can be useful for is the initial two tightenings to "settle" the threads of the bbl nut (if you don't know roughly what 30 ft-lbs feels like).  This is in the FSM for a reason, so I imagine that at some point, bad things happened when they did not do this.  The actual final torque doesn't mean much, though.  You want the first alignment of the bbl nut that allows the gas tube through but isn't sloppy loose.

Quoted: Also, excellent "insider information" about not using the wrench at all. What book or video is going to suggest that?

I know that many (including Mongo ) don't believe in using torque wrenches, but I believe that they are necessary. Your arm isn't a very good measuring device for torque settings. Overtighten that barrel nut and at the minimum you will cant your barrel and at the maximum you will damage the slot in the upper receiver that the barrel extension pin fits into. If you undertighten it, the barrel nut will loosen up and bind the gas tube, not to mention your accuracy will suffer.

The specs call for 30-80 pounds. 99% of the time, if the minimum 30# doesn't align a notch in the barrel nut for the gas tube, tightening it until you do get clearance will not exceed the 80# maximum.

Quoted: Quoted: Also, excellent "insider information" about not using the wrench at all. What book or video is going to suggest that? I know that many (including Mongo ) don't believe in using torque wrenches, but I believe that they are necessary. Your arm isn't a very good measuring device for torque settings. Overtighten that barrel nut and at the minimum you will cant your barrel and at the maximum you will damage the slot in the upper receiver that the barrel extension pin fits into. If you undertighten it, the barrel nut will loosen up and bind the gas tube, not to mention your accuracy will suffer. The specs call for 30-80 pounds. 99% of the time, if the minimum 30# doesn't align a notch in the barrel nut for the gas tube, tightening it until you do get clearance will not exceed the 80# maximum.

M4's right, I don't use a torque wrench, but using torque wrenches is part of my routine at work.  I use one probably at least weekly.  The last thing I torqued was to 800ft/lbf, but that's another story.

Anyway, here's a little tidbit of info for some of you to relate to.  We have a torque tester at work, for checking the accuaracy and function of torque wrenches.  My friend and I, both are pretty strong, tried to see how much torque we could apply using just a 1/2" drive ratchet.  The best that either and both of us could do is 75 ft/lbf and that was pulling as hard as we individually could - hernia producing, forehead vein popping pulling I might add.

What I am trying to say is that a standard armorer's wrench is about the same length as a 1/2" drive ratchet, give or take some.  If you are pulling with what I would consider "normal force", you are probably pulling somewhere in the middle of that 30-90 ft/lbf range.  Start popping some veins and you are getting near or maybe exceeding the range, but you got to be pulling pretty hard.  Stand on it, add extra people, hitting it with a hammer, etc. and you are on your own and could break something.  That is why I don't worry about not using a torque wrench.  The effective length of the armorer's wrench is limiting me to a reasonable amount of torque, if applied within reason.