Wikia

Steel Dragon
Adult Adult - Juvenile Juvenile - Baby Baby - Egg Egg		Available	Level 17
		Buy	750
		Sell	1,500,000
		EXP	100,000
		Breeding Times	14 Hours
		Breeding Times	11 Hours 12 Min
		Incubation Time	11 Hours
Habitats	Metal, Cold	Boost
Limited:	No	Boost
Game Description
The steel dragon likes to parade back and forth showing off its fearsome horns. As other dragons pass, the steel dragon will turn over its right shoulder to flash a cold, steely gaze, stopping them in their tracks. It is a matter of curiosity that no steel dragon has ever been observed to turn left before flashing its gaze.

Breeding

The Steel Dragon can be bred by pairing two basic dragons (one Metal and one Cold) or two dragons that combine Metal, Cold, and at least one other element, in either order, at the Breeding Cave/Epic Breeding Island.

Coin per minute:

Lvl. 1	Lvl. 2	Lvl. 3	Lvl. 4	Lvl. 5	Lvl. 6	Lvl. 7	Lvl. 8	Lvl. 9	Lvl. 10
5	7	10	13	16	18	21	24	27	30
Lvl. 11	Lvl. 12	Lvl. 13	Lvl. 14	Lvl. 15	Lvl. 16	Lvl. 17	Lvl. 18	Lvl. 19	Lvl. 20
32	35	38	41	43	46	49	52	55	58

Dragon Earning Rates without boosts.

Boost Calculation Guide to use with the values above.

The Steel Dragon was added on April 13, 2012.
The in-game description mentions that no one has sighted the Steel Dragon turning left before flashing his steely gaze - this is a reference to the movie Zoolander, a model whose signature look is "Blue Steel" and who is unable to turn left.
According to a DragonVale Facebook post, the Steel Dragon happens to share it's name with the fictional band from Rockstar, a 2001 American comedy-drama film directed by Stephen Herek and starring Mark Wahlberg and Jennifer Aniston.