Gear stats are obtained from forging materials. Each material has one stat:
Hide: Troop load
Hardwood: Defensive building ATK
Thread: Archer ATK
Panel: Infantry ATK
Metal: Cavalry ATK
Stone: Siege ATK
Leather: Troop DEF
Cloth: Troop HP
Bone: Produce food
Jewelry: Produce gold
Glass: Research SPD
Parchment: Building SPD