Typical Small Sizes used in the lighter :
Ø2.00mm (±0.2) Diameter  x 4.5mm (±0.5) Length;
Ø2.10mm (±0.2) Diameter  x 4.5mm (±0.5) Length;
Ø2.10mm (±0.2) Diameter  x 4.6mm (±0.5) Length;
Ø2.10mm (±0.2) Diameter  x 5.0mm (±0.5) Length;

Ø2.20mm (±0.2) Diameter  x 5.0mm (±0.5) Length;
Ø2.20mm (±0.2) Diameter  x 5.0mm (±0.5) Length;
Ø2.30mm (±0.2) Diameter  x 6.0mm (±0.5) Length;
Ø2.36mm (±0.2) Diameter  x 5.0mm (±0.5) Length;

Ø2.50mm (±0.2) Diameter  x 5.0mm (±0.5) Length;
Ø2.50mm (±0.2) Diameter  x 12mm  (±0.5) Length;
Ø2.55mm (±0.2) Diameter  x 5.0mm (±0.5) Length;
Ø2.55mm (±0.2) Diameter  x 6.0mm (±0.5) Length;

Ø2.6mm(±0.2) x 5.0mm(±0.5)
Ø2.6mm(±0.2) x 20mm (±0.5) 
Ø3.0mm(±0.2) x 20mm (±0.5)
Ø3.5mm(±0.2) x   7mm (±0.5)

3/32" Diameter x 2" Length (3/32" x 2")
Reference weight : 0.05 oz/rod approximately
Reference quantity per pound : 320 rods/lb approximately
or
2.38mm Diameter x 50.8mm Length
(Reference weight: 1.42 gram/rod approximately)
(Reference quantity per kilogram : approx. 703 rods/kg;

Larger sizes of flint rod used as the outdoor survival tools:

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              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 :   2.4mm Diameter  x  3.81mm up to 1000mm Length.
 

Application : ferrocerium alloy flints are mainly used as lighter flints for flint lighters, disposable lighters, refillable lighters, gas lighters and welding lighters, etc.,  It is often used as the firestarters or fire starter in scouting and camping, sparking entertainment, clockwork toys, strikers for welding torches, etc., it is the best compact firestarter we can easily use, plus its dependability,made it a favorite of survival experts, hunters, fishermen and campers. It works equally well when wet or dry. it can be used to light stoves and gas-barbecues, it is used as part of earthquake survival kit, emergency kit,  survival kits, survival gear, emergency preparedness kit, disaster preparedness kit Emergency Survival Kit, 72 hour emergency kit, first aid kit, survival necklace, survival neck wallet, etc., also the good companion of the outdoor knife. 

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