Kurt Cobain’s Dean Markley (Heavy) Guitar Stringsaccess_time First seen circa 1991
Unfortunately, not much is known about the exact brand and model of strings that Kurt used on his electric guitars. The only piece of information in regard to the subject comes from one of the interviews from the Musician magazine, in 1992, where Kurt mentioned that he’s using actual piano strings for low E and A.
I use piano wire for guitar strings, ’cause it’s a lot thicker. I buy it in bulk, in these big long tubes, and just cut it to the length of the guitar. They’re thicker than the thickest guitar gauge that’s available. I don’t know what the thickness of ’em is anymore – I can’t remember. I use a really thick E string, and then a smaller size A. A few of the others are guitar strings – I think I use Dean Markley because they’re the cheapest.The Year’s Hottest New Band Can’t Stand Still, Musician, January 1992
However, this was most likely just a joke that over the years developed into a legend. Piano strings would be impossible to fit on most of the guitars that Kurt was using at the time, and if he indeed wanted thicker strings, there were easier ways to achieve that.
One of them would, of course, be to just use a heavier set – which is most likely what he actually did. Going from what he said, that he used Dean Markleys, it may have been their Blue Steel 10-52 set.
Take note however, that this is just a guess. But, that’s all we have since there’s no actual info from Kurt nor anyone close to him.