To make them you need to use the chapter traits (in that section in the codex it tells you what traits you must use).
The Iron Hands have close ties to the adeptus mechanicus, they have lots of master crafted gear and lots of dreadnaughts. They don't have chaplins and commanders a such, they get Iron fathers, they combine the role of priest and commander.
They have a severe hatred of weakness, they view flesh as weak as it isn't strong like metal, thusly lots of their brothers have bionic enhancements.
Thats a brief summary, hop it helps.
The Iron Hands have close ties to the adeptus mechanicus, they have lots of master crafted gear and lots of dreadnaughts. They don't have chaplins and commanders a such, they get Iron fathers, they combine the role of priest and commander.
They have a severe hatred of weakness, they view flesh as weak as it isn't strong like metal, thusly lots of their brothers have bionic enhancements.
Thats a brief summary, hop it helps.