The answer to the crossword clue "Mr Mason's chilly cutters? (4,7)" is "COLD CHISELS." This phrase fits the clue perfectly as "Mr Mason" suggests a worker with stone, and "chilly cutters" cleverly points to "cold" plus "chisels." Cold chisels are hardened steel tools used by masons and metalworkers to cut or shape stone and metal without heating, which aligns with both the enumeration (4,7) and the definition embedded in the clue. This solution is common in cryptic crosswords where wordplay combines literal and playful elements to arrive at the answer.