You wrote as an example, you want to supply the governments jet fighter program. Let's stick with it. It is not the government which does manufacture the jet fighter. Usually that is done by other companies like for example Airbus or Boeing. Both companies have tried to get a huge contract with the Pentagon.
The Pentagon would not buy nuts and bolts from you. But probably Airbus or Boeing would do. Of course they have their suppliers already and it will be hard battle to be accepted from them. It is most often not only the price of the nuts which counts, it is also the reliability or other factors.
The government probably does some engineering stuff on its own - who knows? The problem is we will not know about it and if it is secret, they will not order nuts and bolts as the "US Government" with delivery goal Pentagon. They probably have third names to do that stuff.
So I guess you need to have a good reputation to be considered by engineering companies like Boeing.
Not sure why you want to supply Defense in first, but if I would like to do that, I would read the governments public "call for bids". At least in germany there is a rule that contracts need to go to a "call for bids" first. If you manage to get into on of them - defense or not - you have at least a foot in the door.
Another option is to read the news and try to offer supplying to contracting companies. For example, if you hear Airbus is having a new contract with the Pentagon, try to make an Nuts-And-Bolts offer to Airbus. It will not be easy. But maybe you can make a personal contact in some point of time to get such a contract.
Do research who currently engineers for the Nasa, Government etc. Try to get in contact with them. Do research on upcoming contracts.
I think if you can supply, you'll paid well. Anyway, nobody will accept you as a supplier if you have nothing in hand than your idea and a startup which is not operational. My bet is you need to focus on a specific product to supply, get your startup running, and then you might make it into the desired areas.