I took my torque wrenches in to work and had a standards lab friend check the calibration on my inch # torque wrench,sears 20-250 clicker. I told to him I would be using it to build my plane with. When I picked it up he had a chart of calibration for it and it started at 50 in #'s, I told him the first torque was at 20-25 in. #'s. He said "and your building a plane with this?" yes says I. He goes into a verbal treatise on torque that went on for about 10 minutes. He says there is know way I can use this wrench for 20-25 in. #'s, the bottom 20% of scale cannot be used,he was getting in my face over this. I see on Avery's cat. they mention this also,but then Cleveland says there WT-1501 wrench 20-150 is best for RV's. He says I need a 0-50 in. # wrench to do this correctly and if I use my 20-250 in.# wrench I am off scale out of calibration and I really have know way to know what torque I put on the AN 3 bolt. I see others have used the same or similar wrench and there planes haven't fallen out of the sky,but it looks like he is right and I need another wrench, 0-50 in. #. When it comes to something like this I think erring on the safe side is prudent. What say those that have gone before me? Gene