inflexible

the heavy inflexible armour of the beetles.

an inexorable opponent; a feeling of inexorable doom.See Synonyms at inflexible

Polite but inflexible, she would not be deflected from her intention.

Inflexible "commodity" impression to daughter anchorperson function value.

compared with the railways the canals were inflexible and less effectively networked.

an inflexible knife blade); figuratively they describe what does not relent or yield:

Neither threats nor promises could change his inflexible determination.