A pre-War product of West Tek in conjunction with the United States government, T-51 power armor is made of a poly-laminate composite, shielding the user from radiation and damage while providing increased strength. The armor has a US Army logo and flag decal below the valve on the back. It also has two stars on the front of the shoulder plates and has the serial code DiV:5128417 USA Army on the left side of its breastplate.

• T-51b Power Armor, the classic olive green camouflaged version
• Brotherhood T-51b Power Armor, a light gray version bearing the Brotherhood insignia and used by its Paladins in the Mojave chapter.

• T-45d Power Armor
• Remnants Power Armor
• Enclave Power Armor