Just for kicks I did some searching and found a Hot Rod Network test of torque wrenches. Some comments from that testing:
- We Also Tested The Harbor Freight Unit Against A Snap On Digital Torque Wrench Costing Far More, And Readings From The Two Tools Were Generally Within 0.20 Lb/ft.
- If You Are More The Mechanical Clicker Torque Wrench Kind Of Guy, We Also Tested Harbor Freight’s 1⁄2 Inch Clicker Torque Wrench, And It Was Also Very Close. It Also Has A Range Of 20 To 150 Lb Ft And A Lifetime Warranty. Accuracy After Five Consecutive Tests At 70 Lb Ft Ranged From 68.8 Lb Ft ( 1.2) To 70.3 ( 0.3), With An Average Error Of 0.30 Ft Lb Over Five Tests. It Doesn’t Get Much Better Than That For A Mechanical Torque Wrench.
Source:
Torque Wrench Testing - Shop Tools - Hot Rod Network
Ah, but how well does a HF torque wrench stand up over time? Well, check out this test of an 8 year old HF wrench:
https://www.youtube.com/watch?v=RZR92kNpoRQ
The bottom line: There are certainly feature (e.g. ratcheting head # of teeth) and quality differences between higher-priced or name brand torque wrenches, but the low-priced tools are accurate enough to get the job done.