Ferrocerium rod is made from Iron, Magnesium and mostly of an alloy of rare earth metals called mischmetal with an excellent pyrophoric percentage :  98%min.
The required chemical composition:   
Mischmetal(rare earth metal)  76%MIN.
Fe (Ferro or Iron)     18 ~ 21%
Mg ( Magnesium )    1.5 ~ 2.5%
Hardness :               90 ~ 170 HB
Surface   : black lacquer coated, natural grey, colored 
Size available :   3/8" (9.525mm) Diameter  x  5mm up to 1000mm Length.

Ferrocerium flints are used used for the sparking pads, these ferrocerium rods have various length and the same diameter, then clip-on and self-adhesive sparking pads for the sports devices such as, skateboard, to generate sparks when the pads come in contact with a hard surface, such as cement(street), asphalt(sidewalk), or metal(railing), etc.,

The sparking paid is a skateboard accessory that sticks discreetly on the deck and produces a shower of hot sparks when you drag your tail of skateboard on the ground.

Sparks will vary with the amount of force applied, the length of dragging, and the coarseness of the skating surface.

This sparking pad fits on most skates and does not screw up your skating, it will eventually wear out and you just rip off what is left and start over with a new ferrocerium rods.

Trade names : ferrocerium flint sparks for skateboards, skateboard accessories, sparks skateboard, skateboarding sparks, skating in sparks, sparks for skateboards, rare earth material, rare earth ferrocerium mischmetal flint, flint sparking element, sparking spare parts, flint sparking pad, flint sparking pads, flint slab, flint slabs, ferrocerium slab, ferrocerium slabs, cerium sparking flint, cerium sparking flints, etc.,