I recently read an article in Airborne magazine which I do not entirely agree with. As a musical instrument repairer I am knee deep in piano wires every day, and after 38 years of wrestling with the stuff I am sure I can offer a few tips on taming the beast.

Choice
My experience is that the colour of the wire can be a guide to its quality. Usually wire of a dull grey colour will be far less brittle than the bright and shiny (almost silver) colour that comes in kits from the Far East.

Bending
Small diameter wire usually does not present much of a problem, however larger diameter can present a real problem. What is needed is a propane burner, one of the jewellers pin-point burners is ideal and can be purchased from large hardware stores. A good vice; a good hammer and some reasonable arm muscle is also a must. Try the following on some small scrap bits first till you get the hang of it.
The secret is how much you heat the wire, too much and you have ruined it forever, not enough and it will break. Carefully heat the wire just where you want the bend to a colour just past blue, halfway between the blue colour and dark straw. Quickly transfer to the vice, and make your bend, being careful not to make it too sharp. Proceed with all the other bends you want to make, then let the wire cool naturally without quenching. Now proceed to normalise the entire piece by heating the whole thing to just a dull purple colour, no more, and dunk in a previously prepared bath of oil. Any mineral oil will do. Remember to always wear safety goggles just in case!

Drilling holes
Yes, you can drill piano wire! For things like split pins in scale undercarriages and for any other reason. It is best to use a Carbide drill of the right size that can be bought from an Engineer's supply house (not an ordinary hardware store!). Remember to use some lubricant when drilling, if you do not have any cutting oil then ordinary lubricating oil will do. You must first grind a small flat area on the wire and centre punch it otherwise your drill will slip on the wire.
Remember that Carbide drills are very brittle so drill carefully when you are getting near to the "break through". You can drill a hole with an ordinary drill if you cannot bring yourself to buy a Carbide one, but the hole must be in a spot on the wire that has no stress on it, such as the very end of the axle to retain a wheel.
Heat the very end of the wire to a bright cherry red just at the end where you want to drill, and while it is still glowing quickly start the drilling. You will have to re-heat a few times before you get through the wire, the heat will not unduly affect the drill (as long as you don't heat the drill with the torch).
Tapping
You can actually tap a thread in the end of piano wire as well! The top wing of my Fokket Triplane is held on this way! The thread will have to be consistent with the diameter of the wire of course. Grind a "lead" on the end of the wire first, this can be ground off later. You will need a good quality ground thread tool steel die (not the cheaper carbon variety) and again heat the very end of the wire to dull purple and quickly thread while it is still hot. Nomalise after you have finished as previously explained.
Happy bending/drilling/tapping. Remember that practice makes perfect and always test the final product before you bolt it into your favourite creation in case you made a mistake and you have embrittled the wire.