Answer: annealed

AnswerCrossword Clue
ANNEALED

Did a glassblower's job, perhaps

ANNEALED

Strengthened by heating

ANNEALED

Toughened, as glass

ANNEALED
Tempered and rendered malleable.
ANNEALED
Tempered, as steel.
ANNEALEDTempered
ANNEALEDHeated, as glass
ANNEALEDGot hot, then cooled off
ANNEALEDToughened
ANNEALEDTempered with heat