Board Thread:Questions and Answers/@comment-69.143.181.86-20121228002841/@comment-108.216.203.52-20121231044558

Tungsten is an RP block. not an EE block. Elo has stated that she plans to use it, but implemented the block well before actually needing it. (This was before the rapid updates from 1.2.5 to 1.4.6) She's only just now managed to push a pre-release to 1.4.6, so I'd expect that to be the next version of Tekkit as well.