The fibers allow the concrete to bend and crack in narrow hair-width fractures rather than gaping splits.

纤维可以使混凝土弯曲并出现头发丝细的裂纹，而不是直接裂出口子。

youdao

This is a single fracture that is very small, like the width of a hair.

VOA: special.2009.02.04

The neutrons are shot between two parallel plates, one above another and separated by about 25 micrometres - half a hair's width.

BBC: Neutrons could test Newton's gravity and string theory

One side of the silicon can then be etched down to within a fraction of a hair's width of the glass layer, leaving the other side as a support.

ECONOMIST: Chip technology

The N95 blocks 95% of particles bigger than 0.3 microns, or one-three-hundredth the width of a human hair.

FORBES: Magazine Article