In this solidworks tutorial, you will create simple allen key.
1. Click New. 
Click Part, 
OK.
2. Click Front Plane and click on Sketch.
3. Click Line, skecth a L shape.
4. Click Smart Dimension, 
and dimension sketch as 2.5″ and 1″.
5. Click Sketch Fillet, 
add 0.3″ fillet at L corner.
6. Exit sketch, 
click on Top Plane and click Sketch.
7. Click on Sketch2 and click Normal To.
8. Click Polygon, 
sketch a polygon at origin.
9. Click Smart Dimension, and dimension sketch diameter to 0.15″.
10. Exit sketch, click on Isometric view.
11. Click Features>Swept Boss/Base, 
for profile click on Sketch2 and for path click on Sketch1 and OK.
You’re done!.
