Piano Wire

Free Acids. — A solution of 30 gm. of copper and ammonium chloride in 100 cc. of water must be perfectly clear, On introducing into the solution several pieces of piano wire, the latter should dissolve with the deposition of copper, but without any evolution of gas. 

Metallic iron is used in the analytical laboratory in the form of thin, polished wire (piano wire), or gray powder obtained by reduction with hydrogen (iron by hydrogen), and also in the form of the ordinary gray, lustrous powdered iron. 

Cold-working is frequently used for hardening of commercial metal products. Thus, piano wire and the wire used in bridge construction obtain their hardness as a result of (he final wire drawing operations. Sheet stock is often supplied in different degrees of hardness obtained by cold-rolling to the desired hardness. Mechanical working is sometimes the only feasible way lo harden specific metals and alloys. 

The effect of cold-drawing of wire upon the density of the metal is clearly shown by the following data, obtained 4 with iron piano-wire. The density has been calculated for a vacuum at 4° C. 

The piano wire garotte has the advantage in that it is less likely to be seen going over your opponent s head, and it tends to cut his hands If he tries to interfere. Its disadvantages are that It tends to leave blood behind, and... 

Other screening surfaces include "rod decks , which reduce pegging and blinding, and piano-wire screens, which are less prone to blind when screening fine, moist products. An alternative approach for moist materials, which are prone to blinding, is to use heated decks. TTiese use stainless steel (which has a higher electrical resistance than mild steel), woven into a wire mesh, through which an electrical current is passed. 

Piano-wire Screen. A screen formed by piano wires stretched tightly, lengthwise, on a frame 2-3 ft (0.6-1 m) wide and 4-S ft (1.3-2.6 m) high. The screen is set up at an angle of about 45° and crushed material is fed to it from above. The mesh size varies from about 4 to 16. 

FIG. 7-5. Apparatus of Fujino, Kawai, and Horino for measurement of dynamic Young s modulus of fibers by free vibrations. (A. A ) Chucks (B) sample fibers (C) clamps (D) inertial disc (E) idler pulleys (F) piano wire (C) mirror to reflect light beam (H) weight to adjust static tension. 

C—Spring—piano wire cylindrical helical compression spring with six active coils, eight total colls, wound dosed, ground square, and cadmium plated D—Washer—22 25 mm (Ve In,) OD, 12,7 mm (V in.) ID, 1.6 mm (Vie In.) thick —Nut-12.7 mm Vs in,)—20 NF F—Test specimen... 

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