Caught myself torquing head bolts without a torque wrench for almost a month

About 6 months ago I was doing a head gasket on a 7.3 and I realized halfway through the final torque sequence that I had been "torquing" to spec by feel on the last 3 engines I touched. I'm not kidding, I would set the wrench and then just kinda stop when it felt tight. The thing that tipped me off was my arm felt tired at the same number on the dial every time, which is not how a torque wrench works at all. I grabbed my beam style wrench out of the bottom drawer and checked a bolt I had just done, and it was maybe 60 ft lbs when it should have been 85. I sat there in the bay for like 10 minutes just staring at it. All those jobs I sent out the door and I'm lucky none came back with a blown gasket. Went out and got a decent click type the next morning and I check it against the beam one every couple weeks now. How do you guys keep track of calibration or do you just trust the wrench?