My three torque wrenches are teng, 3/8, 1/2 and 1", the 1/2 inch one went mental and just went limp(I know the feeling), viagara didn't help so I went back to the teng dealer, didn't have one in stock, needed it urgent I told them(I didn't!!) they sent one by courier, same day as replacement from nearest dealer with one in stock, they took it out of a set.
Never had any other issue with teng, unlike snap on, I changed from snap on to teng as 3 times repaired snap on torque wrench in 4 weeks broke in the snap on dealers hands as he tried it on a wheelnut, snap on refused a refund of the repair, so f**k em I say.
tabetha