crackless

From crack +‎ -less.

crackless (comparative more crackless, superlative most crackless)

1. that lacks cracks
   • 1972, {unattributed}, Periodica Polytechnica: Civil engineering. Bauingenierwesen, Volumes 16-17

     "However, the structure remained crackless, i.e. it was in the so-called first stress state."