Maybe I read an older test, but the Hitachi NR90AC3 is ranked #1 in the 120 psi class
http://www.toolsofthetrade.net/industry-news.asp?sectionID=1491&articleID=501037
We tested the Airy AUA 219OC, Fasco-Beck R5C RHN 20-90 SS (CT), Grex SF9021,
Hitachi NR90AC, Interchange Brands ICB-FN88, ISM Fastening Systems 921 ProPower, ITW Paslode F-350S, Jamerco JTNFH90A, Makita AN922, Max SN890RH, Porter-Cable FR350, Senco FramePro 750 XL, Spotnails NPR90, Stanley Bostitch N88WW-1, and the UNI Ultra Tools/Apach AN-9034AC.
Winner's Circle
We found Hitachi to be the best nailer in super-hard, high-density engineered lumber. It performed perfectly in the yard and on the job. Second place goes to the UNI/Apach, Makita, and Stanley Bostitch nailers. Next we'd recommend the Fasco, Paslode, Max, Senco, and Porter-Cable models. They had ample power and tolerable recoil. And finally comes Airy, Interchange, Jamerco, and ISM.
The Grex and Spotnails models are fine for most framing applications, but I wouldn't recommend them specifically for nailing engineered lumber. They didn't produce the power we need for the wide array of materials we encounter.
Michael Davis is president of Framing Square, a large framing, siding, and trim company in Albuquerque, N.M., and is a contributing editor to Hanley-Wood's Tools of the Trade
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