Ordnance Factories Day is observed on 18 March each year.
Ordnance Factory Board is an industrial organisation, functioning under the Department of Defence Production of Ministry of Defence, Government of India.
It is engaged in research, development, production, testing, marketing and logistics of a comprehensive product range in the areas of air, land and sea systems.
OFB is the world's largest government-operated production organisation, and the oldest organisation run by the Government of India.
It is often called the "Fourth Arm of Defence", and the "Force Behind the Armed Forces" of India.
The production of India’s oldest Ordnance Factory, which is at Cossipore of Kolkata, was started in 18th of March, 1802.