Green’s Dictionary of Slang

(US Und.) a safe-breaker.

1872		E. Crapsey Nether Side of NY 16: Safe-blowers do not have more than seventy-five names upon their muster-rolls, but the little army is far more dangerous to the hoarded wealth than its numbers indicate.
1886		T. Byrnes Professional Criminals of America 🌐 The most reckless of the safe robbers use explosives [...] The men who resort to explosives are known to their associates as ‘blowers’ They are daring and desperate fellows and acquainted with the use of the drill and high explosives.
1914		H. Hershfield Abie the Agent 16 Feb. [synd strip] He’s a crook — a benk blower!
1928		M.C. Sharpe Chicago May (1929) 260: Peter Men, Yeggs, Blowers—safe crackers.
1972		E. Grogan Ringolevio 205: He moved out to a house in East Dulwich with a safe blower he met in the Brixton nick.