I was never a professional mechanic, but in all my DIYing I never did feel like I really needed a torque wrench.
I was never a pro either but I have 4 of them, 1/4, 3/8 and 1/2 plus a click type 1/2 because I can no longer bend over and read a torque wrench when doing lug nuts.
I have one and used one the few times I rebuilt an engine an needed to torque down the head bolts. I do have a tire torque wrench though. Can only be set to 70-100 ft/lbs.
Never did a cylinder head, I guess? Or you just guessed on it? If so, and it worked, then you got lucky. The same goes for similar critical applications. You can fudge your way through a lot of things. But if you want to know it’s right, a decent torque wrench is the only way to go for certain things.
The only cylinder heads I ever did were single and twin cylinder motorcycle engines. If I had ever done a multi-cylinder I probably would have looked at a manual and then guess-timated by elbow-feel.
I use my torque wrenches for stuff with a gasket that could leak if not properly torqued (e.g. head bolts, intake bolts etc), suspension parts that are critical (ball joints, steering, misc suspension) and for setting the torque on axle nuts for unitized wheel bearings. The latter is critical to long life and IMO cannot be properly estimated…
Bolts includes nuts also…
I normally torque, main caps, rod caps, head bolts, rocker shaft bolts, intake manifold bolts, any bolt in/on an engine not seen once assembled, including gasketed parts, flywheel/flexplate bolts and harmonic balancer bolts, all transmission bolts except bell housing bolts, all differential bolts not including mounting to the vehicle bolts, wheels and hub axle nuts and anything over probably 100 ft-lbs (like those Ford 184 ft-lbs caliper brackets)…
I have 4 torque wrenches 1/4, 3/8 x2, 1/2" drives…
What’s the torque range on that 1/4"? And I assume it’s scaled for inch pounds? Just curious. I have a 3/8" that goes down to 20 in.lb., and tho I can’t recall ever needing to go that low, I never do trust those at the extremes of their range.
Don’t remember the range but it is a beam type in inch pounds, mainly used for checking pinion bearing pre-load torque (seal removed)… So at least down to 10 inch pounds… lol
But I am thinking it is either 0-150 in-lbs, or maybe 10-150 in-lbs, but don’t hold your breath…
It is in my tool box at the other garage, hope that will change next week…
Your post triggered memories of torquing those crush sleeves on my older Chevy trucks with the diff still installed. Without aid of a lift for clearance, getting that kind of force to start the deforming process was a huge challenge…
I went with the crush sleave eliminator kit on my 8 3/4 rear end, so it was a lot of testing to get the correct pre-load… But yeah, done the crush sleave many times… lol
BTW, try torquing the pinion nut to spec with the pumpkin on the floor w/kick stands, had my daughter standing on the pumpkin while my 275# (at the time) self stood on the torque wrench trying to get it to spec… 
My dentist used a miniature torque wrench when I had an implant. There is a specific value to which the implant post is torqued. Any work done concerning the head, be it human or automobile requires a torque wrench.
I used the 1/4" to torque the internal and external bands on Torqueflight and powerflight transmissions in inch pounds.
I no longer need a torque wrench, quit wrenching.
Decades-old implant started to get loose, so current dentist had to drill into crown and tighten it, using a torque wrench.
Seems I had a screw loose…but then my wife could had told you that!
I have noticed my increasing torque sensitivity regardings jar tops:
10 ft lbs for spaghetti sauce
20 ft lbs for jam/jelly
30 ft lbs for relish
100 ft lbs for those little olive jars!
etc…
But seriously, invest $69 in a torque wrench for tire lug nuts.
Safety first!
Funny!
It seems the force required is often inversely proportional to the desire to access the contents…
