piano wire

Hey all,

Many sources talk about aircraft held together by piano wire.
I've been wondering how long did they use it 1914,15,16... also what grades does the wire come in - just how strong is it? What other types of wire were used.

thanks in advance,

jbs

Piano wire is used in musical instruments and for winding springs. the wire is very strong, Theatrical use of "piano wire" makes Peter Pan fly! IIRC, .049" dia over a pully and counterweight attached.
In a/c piano wire is mostly seen as drag bracing in a wing and or diagonal truss bracing in the bays of the fuselage. Although still used in restorations etc. wire bracing gave way way to tie rods. the week point of the wire bracing system, as used in aircraft was slippage of the ferreled loop at each end. Also, today, ferrels are no longer available from the wire manufacturers. The copper swaged blocks are better, but not authentic. My local OSH (owned by Sears) store carries quite a selection of various piano wire rolls. they also carry a/c cable! Unfortunately they don't carry any aircraft approved attachment methods.
Charlie

[Dan_San_Abbott]

jbs:
British specification "High Tensile Wire" (music wire) came in 13 standard wire size from No.6 , .192' dia, 5500 lbs. ultimate tensile strength and rated at 65% at 3600 lbs allowing for joint efficiency to N0.24 at .022" diameter, with an ultimate strength of 102 lbs., and rated at 66 lbs.
Blue skies,
Dan-San

[AchimEngels]

Hello,

In Germany we used steel wires which have been available in strenghts between 150-250 kg/square millimeter. The diameters of these ranged between 0,16-12 mm.

Rheinische Aerowerke located at Düsseldorf for instance delivered steel wires with a strenght of 150kg/square millimeter in the folowing diameters:

0,5mm / 0,75mm / 1mm / 2mm/ 3mm / 4mm / 5mm / 6mm

They furthermore delivered steel wires of 250kg/square millimeter in the same diameters.

Gebrüder Böhler & Co have also been suppliers as the company of Emil Fenner was.

In Germany we used this kind of steel wires until the end of the war.

Such piano wires can still be purchased easily in Germany today. We call it "Klaviersaitendraht"

(According to Prof.Dr. Huth, BAUSTOFFE UND BAUTEILE DES FLUGZEUGES, published in 1918 by Richard Carl Schmidt & Co.)