困难的 (adj)

hart (adj)

hard (adj)

This brings about a change in the material (e.g. hardness).

The tool materials must be harder than the workpiece.

Software / program codes on diskette or CD-ROM and in hard copy

stiff (adj)

Stiffening ribs increase the elastic stability of the support.

These stresses are counteracted by stiffening plates welded in at regular intervals.

Additional stiffening plates and stiffening ribs can be used to help maintain the cross-section under load.

duro (adj)

rígido (adj)