point de fer

CONT: Les prix des minerais de fer sont donnés essentiellement de deux manières (...). Pour s'affranchir de la teneur en fer, ces prix sont toujours ramenés au point de fer (on rappelle que la base du prix de la tonne est le point (ou unité) de fer, c'est-à-dire la teneur en fer en % (1 % = 1 point), établie habituellement sur minerai sec).

CONT: Another form of expressing iron ore prices is cost per iron ore unit, which is a more universal convention that can be used to compare ores with different grades in each product form. One metric ton iron unit consists of 1% iron in the metric ton of ore or, expressed directly in weight, one metric ton unit consists of 10 kg of iron. Accordingly the price of a ton of iron ore is obtained by multiplying the price of an iron unit by the grade of iron expressed in percent.
OBS: Pellets (per tonne natural iron unit). ... Equals 1 per cent of a tonne. A 60 per cent iron ore, therefore, has 60 units.