Some of the best for drop tuning

I have tried these on many different guitars through the years, on all kinds of tunings ranging from standard E through drop D, D, C and all the way down to B (yes, on a 6-string!) and they deliver!

If you want to go as deep as B a Floyd Rose or similar equipment might be necessary (it's hard to tune a strat that low in my experience), but for D or just drop tuning these are also great.

Heavy, thick, easy to play and with a good ring to them. Excellent for playing metal and blues, probably for jazz as well.