Where do you get the graphite? Go to the store any buy it?
whittle a point on the end,
Where do you get the knife to whittle a point on it?
and place in a simple, reusable wooden clamp,
Where do you get the clamp?
formed from two sticks and a metal sliding band
where do you get the metal? How do you form the band? To do all of these things you have to interact with someone else.
You stipulated that the raw materials were available.
Where do you get the knife to whittle a point on it?
Gee, you got me there. I assumed that technology widely available since paleolithic times was assumed to be available to my manufacturing. Gosh, I guess I'll have to smelt some ore, forge some billets and sharpen a resulting chunk of steel. The question was "how do you make a pencil from raw materials?", not "how do you make a pencil if dropped naked onto Mars?" May we also stipulate that the date of manufacture is today, and the location of same is any human occupied municipality in the U.S.?
Where do you get the clamp?
From a chunk of wood. Raw materials were stipulated, remember?
where do you get the metal? How do you form the band? To do all of these things you have to interact with someone else.
What's your point? That trade is necessary? That someone else does not need to be in Indonesia. Indonesian pencil, spice or tea production is cheap for one reason: transportation energy costs are fabulously cheap today. The physical production of goods is easy practically anywhere, given the raw materials and available labor. It's getting the raw materials to the labor and the finished product from where it's made to where it's wanted that is the key to trade.
If pencils could only be made in Indonesia, they would cost like rubies, but they aren't. They can be made anywhere on earth by any marginally sentient person with widely available materials. So, why not make your own? Because time is the one commodity that cannot be traded, and my own personal allotment of time is more profitably used in other ways. When the Indonesian pencil maker has more profitable ways of using his time, he won't make them either, and either pencils will cost more or be manufactured in Malawi instead.
But the whole discussion is a red herring. Pencils are not a vital commodity supplied from limited foreign sources along a supply line with multiple point-failure junctions. The safety and economy of the U.S. may not rely upon pencils, but it does rely upon steel and heavy industrial products, and abandoning the ability to produce these is as short sighted as selling your water rights in a drought prone area because of a few rainy seasons.