Typical Size :
3/8" thickness x 3/8" width x 3" Length ( 3/8" x 3/8" x 3" )
Reference weight : 2.05 oz/bar approximately
or 
9.52mm Thickness x 9.52mm width x 76.20mm Length
Reference weight :  58 gram/bar approx.

Ferrocerium rod is made from Iron, Magnesium and mostly of an alloy of rare earth metals (or rare earth elements) 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 

We can tailor to your drawings or designed shapes, such as ferrocerium flint half round (half lengthwise with semicircular) rods, Ferrocerium flint plate, Ferrocerium flint sheet, Ferrocerium flint round bar, Ferrocerium flint round bars, Ferrocerium flint round rod, Ferrocerium flint round rods, Ferrocerium flint flat bar, Ferrocerium flint flat bars, Ferrocerium flint square bar, Ferrocerium flint square bars, Ferrocerium flint square block, Ferrocerium flint square blocks, Ferrocerium flint disc, Ferrocerium flint discs, ferrocerium flint half round rod, ferrocerium flint half round rods, ferrocerium flint half round bar, ferrocerium flint half round bars, ferrocerium mischmetal flint, ferrocerium mischmetal flints, etc.,