SPIROL has a standard offering of Straight Pins, Knurled Pins and Barbed Pins.
General guidelines when a Solid Pin may be suitable: a need to manually align several clearance holes, precise hole locations need to be maintained, increased bending or shear strength is required, or a hollow pin is not suitable such as when the designer is looking to plug a hole (i.e. Restrict passage of liquids)
Solid Pins may be the solution when a head is required for a positive stop or to retain a thin member to a thicker member of the assembly or when a smooth, uninterrupted surface is required such as when used in conjunction with a pawl or other angular component.