One of the original Warpath factions, the Forge Fathers are
squats Space Dorfs done right, which means of course that they're just straight-up Warhammer Fantasy Dwarfs with Space Marine armour. Their basic troops are the Steel Warriors, wielding space tommy guns and stupid-looking beak-beard helmets, and Stormrage Veterans who fight in bizarre, crystalline-looking powered armour with even bigger space tommy guns. They probably mined a planet too deep and released some ancient evil or some shit, hold long grudges, hate psychics, have the best technology, and cream their space pants over beards, beer, and gold, because that's what dwarves always do. Case-in-point; concept art posted during the latest Kickstarter showed even their tanks have beards!
Nowadays they probably are the posterboys of the warpath universe alongside with enforcers, and they are both considered space marine equivalent in terms of weapons and armor. But enforcers would be Ultramarines equivalent, whereas Forge Fathers are Space Wolves equivalent, hence forgefathers are the manlier variant, armed with sweet sweet weapons named after norse mythology and without that much wolf fetish and much more thunder and fire fetish.
It is heavily implied in the background that forgefathers could make the corporation tyrannical rule over the galaxy end, but as of the current storyline they are not caring and or trading with them to openly to actually desire to take them down.
Also Forge Fathers have several subsections, the most know is the Brokkrs, pronounced Brokers that are space faring, motorcycle riding(yep mantic went there), axe wielding, drifter bald black dwarfs(mantic went there too, though not all are black, but originally they were sold as such, their leader is still white though). Overall Brokkrs offer a secondary interesting spin in the already interesting spin that mantic took.
They are also present in dreadball as a forge father and brokkrs team, playing the tipe of football you would expect from dwarf teams, so they arent really that competitive, but their models are by far the most gorgeous