Walls and Ceilings - Building a wall under a beam

I'd like to frame a new wall in my basement. I'd like to place the header under an existing metal beam - How do I secure it to the beam? ( I can't imagine trying to drill through the beam - it would probably take forever & be nearly impossible.) When one wishes to do this how is it normally done? Do they make some kind of fasteners to accomplish this task?

Drilling shouldn't be that bad as most I beams aren't a real hard steel, I use a drill in a wood "cradle"/post with the bottom on a small bottle jack. I hold the top and the drill trigger, a helper keeps pressure applied to the jack and you'll make short work of it.
but if you've ruled that out:

--you could go rent a Ramset gun and get loads that will penetrate steel.

--you could go rent a wire welder and tack pieces of metal angle on either side of the top of you wall to hold it in place.

--I suppose you could even glue the top of you wall to the steel with some epoxy glues

and probably a couple other ways I haven't thought up yet.

Should not be a problem. I've drilled from the top of the flange downwards, not up. You can do it between the joists easily. just get a sharp drill bit which equals the diameter of the nail you want to use.

Could I use my 18Volt cordless drill with the right bit? Carbide bit?
I have to drill from underneath it.

Carbide bits are for masonary, use a regular twist drill.

A cordless might do it, you just may have to swap batteries a lot.

To drill steel like this, I use a heavy duty variable speed drill. The key on drilling steel is to keep the speed of the drill low, if you're pulling long, stringy pcs out of the hole, you're about right on the speed......don't go as fast as the drill will go, you just burn the bit.

Thanks for the feedback. I'll give it a try and see how it goes.

I tried drilling a test hole & it actually wasn't too bad. I was planning on using screws to fasten the header to the beam. Any suggestions on the size and type of screws? lag bolts? etc?