Did anyone yet notice that mining can be grey, plain and boring, even with a Mining Drill? Now, of course it is, because it's still hard work and a hell of a lot of stone to mine through. Some people claim TNT-mining to be far more fun; and for sure it is. On the downside however, using TNT to mine stuff reduces your overall mineral gain by 70% due to explosion casualties, not to mention the extreme danger of working with explosives... For this sole reason, we invented industrial TNT.
Splitting up the charges and adding some nice cutting material results in the explosion caused by our patented ITNT to be much more useful: It has less direct power, which means no more accidental suicides and destroyed ore. The only downside; its fuse is slightly shorter (due to economic reasons) and its blast radius is slightly, slightly smaller than that of normal TNT. Did I mention you that can used the divided parts of the three TNT charges to form a 4th ITNT charge? Yes, this means you can effectively increase your overall TNT gain by 33%! HAYO!
See: Crafting Guide
Industrial TNT will explode if punched, unlike regular TNT.