you choose to use as a burnisher, it must meet two requirements:
1. The steel must be harder than the metal you wish to bend. The reason here is obvious.
2. The steel must be smooth and free of chips, ridges and other imperfections that would be transferred to the edge of the blade you are creating. Think of grinding the profile of a beader iron if you want it more graphic!
The exception to rule #2 is if you want to scrape paint or glue. Then it does not matter. Use a coarse file instead if you wish. See if I care.
Frankly I am amazed that so many want to cut corners on this important tool simply because they consider a cabinet scraper to be basic, cheap and elementary. Would you prepare the blade of your scraper plane or the blade of your finish smoother with this lack of concern or care?
There are indeed shortcuts in the expense department, but they are not available to every one - it depends on opportunity and availability. For example, I made this burnisher out of a carbide rod that was a present to me from the owner of a machinist's shop (thanks Tony)..
For reasons of "a return-to-sanity", I stopped using the pinion gear as a burnisher, although it worked very well (Guess the car and you can have it - the pinion gear, not the car! - free except for shipping costs!) ..
If you do not have access to carbide (e.g. a nice friend or a router shank ... what is a router shank you ask on a hand tool forum ... good for you!), then buy a burnisher! Don't be cheap and use a screwdriver shank - it violates Rule #2 above.
The LV is excellent but some may find it fussy because it offers options. The Hock also receives great reviews. I have used a Crown for a number of years. Still have it. Here is a picture alongside the homebrew burnisher (which lets you see how small and slim the carbide rod is – I am convinced that this is an advantage over the thicker rods. It seems to require less downforce. This may also be due to the carbide itself since it is self-lubricating - love this one!) ..