Can someone help? How to create a hammer?
A few ways are possible:
If it’s really simple, think out the coordinates of the vertices before hand and use a
glBegin(GL_ what you want);
You could even aply a texture to it to look better.
Use a tool as 3ds max, maya or others that are there for 3d model creation, then
2a somehow export their coordinates
2b use a file loader for the model you created.
You can use vertex arrays or lists to speed things up a bit as well.