Hole drill and long drill bit...

[amecks]

What is the intended use of this?   Obviously a drill but what for and how would one use it?
The hole saw can be reversed and just screws on.  The pin - very sharp - is spring loaded.  The allen screw holds the pin and spring in place. (No markings)

What is purpose/use of this long thin drill bit? 

[geneg]

First item looks like a spot weld cutter.  Or possibly a cutter to remove the idle screw plugs from a carburetor. 

[Bill Houghton]

Long drill bits have endless uses.  I have a few, some from my uncle, some from yard sales.  Drilling deep holes, obviously; but also holes that need to be somewhere down in an awkward spot, where you can get the bit in but not the whole drill.  Stuff like that.

Does it have a cross hole through the root of the flutes, an inch or so back from the tip?  If so, it's a bell hanger's bit, used to drill up through the framing in a wall and pull doorbell wire back through the hole (you push the wire through the cross hole, wind it around the flutes so that it doesn't stick out past the body of the bit, and you can pull the bit back, with the wire following through the hole.  It looks a bit small for that, though.

In small diameters, the really good bits are tempered so that they're flexible and less likely to break.

First item: spot weld cutter does seem like a possibility.

[Aunt Phil]

Looks like a Blair hole cutter.
They are popular in aircraft repair and auto body for cutting panels away from spot welds. 

Drill bit is a pulley drill.  Usual use is for drilling the hub of a pulley or wheel so it can be tapped for a set screw.

[oldgoaly]

agree with the spot weld cutter with a replaceble center drill. tip should be 135* grind for sheet metal (118* is for other stuff)

[amecks]

OK.  Thank you all.  Bill, the bits are very thin and very flexible.  Maybe 1/16"?
Al

[Bill Houghton]

Not bell-hanger's bits, then.  I don't know exactly for what purpose long bits that diameter were originally developed; and I can tell you I don't have any that tiny.  But I can tell you the slightly larger bits I do have get used at least every couple of months.  Whether that will still be true on the - possibly mythical - day that we've finished the major refurbishment of the house, I don't know; but they sure solve a lot of problems now.

[leg17]

Long and extra-long drill bits have multiple applications.
Like, drilling deep holes.

[gibsontool]

I had a set of 16"long bits that I got at Princess auto which is the Canadian version of your American Harbour freight. they original set had, I think, 7 bits from 1/8" to 1/2" I've had them for probably 10 years or so and out of the original 7  I still have 4 of them left which is pretty good considering the quality and the use I've got out of them. The 2 smallest were the first ones to go and I just recently broke the 7/16". Time to start looking for another set because they come in handy in a lot of applications and they don't seem to be some thing that is always in stock.
 The first bit looks interesting, never seen one before, looks like it would work well to drill out rivets. Are these a common Item?

[Lewill2]

Checkout my old standby McMaster Carr I have gotten extra long drill bits from them in the past for hard to reach places for work. Not cheap but they have them, at least they use to carry them. You can buy individual sizes.

[Bill Houghton]

My hardware store carries long bits.  I haven't checked - not needing to - but I imagine the big boxy stores do, too.  They're not rare.