When last we visited Steinway No. K0862 in the N.Y. Times‘ ongoing series, woodworkers had built out the rim and added the keybed. Now it’s time for the intricate installation of the hammer and key mechanism that will ultimately define the precision “action” of the Steinway. The motion of the keys, the action, is what a pianist will feel, the heartbeat of the instrument itself. The action must not be too light or too hard. “Two grams, plus or minus a gram” is the tolerance of the force to move the hammershank. Behind each of the 88 notes, each of the 88 keys, are 54 parts that make that one tone happen. The piano I played growing up (not a Steinway) had a few keys that would stick in humid weather. At one point in time, Steinway used Teflon bushings to avoid that problem. But the Teflon solution caused clicking noises and was eventually dropped in favor of soaking the bushing material in Teflon, which seems to help. Surrounding the technical details of the continuing construction of K0862 is coverage of contract negotiations between Steinway and its workers, and the company’s plans to stay ahead in an uncertain economy.