A cross-section must be set out and drawn in the same manner as a normal view whose parts in cross-section are hatched with regularly spaced parallel oblique strokes, the space between the strokes being chosen on the basis of the total area to be hatched. Hatching should not impede the clear reading of the reference signs and reference lines. Consequently, if it is not possible to place reference signs outside the hatched area, the hatching may be broken off wherever reference signs are inserted. Certain types of hatching may be given a specific meaning. The hatching should be at a substantial angle to the surrounding axes or principal lines, preferably 45º. The various parts of a cross-section of the same item should be hatched in the same manner. The hatching of juxtaposed different elements should be angled in a different way. In the case of large areas, hatching can be confined to an edging drawn around the inside of the outline of the area to be hatched.
PCT AG I 5.149