Green’s Dictionary of Slang

cracking n.

[crack v.2 (2d)]

(UK Und.) housebreaking; also attrib.

Manchester Wkly Times 23 Aug. 11/3: They tell of deeds of darkness, some of which in the cracking line would cause the blood of an honest man to run cold.
[UK]Leaves from Diary of Celebrated Burglar 10/2: ‘Buzzing’ at that moment was high in the market, while ‘cracking’ appeared to me considerably below par.
[UK]Sportsman (London) ‘Notes on News’ 26 Jan. 2/2: When a ‘gentleman’ is detected in the area of another gentleman’s house, provided with a cord, a short poker, a ‘jemmy’ [...] one cannot help coming to the concluion that a little ‘cracking’ business is in the wind.
[UK]J. Greenwood Tag, Rag & Co. 33: There’s nothing too bad for them jokers, from smuggling to cabin-cracking – boarding coasters and that sort of craft left at anchor [...] and breaking into the captain’s cabin.
[US]C.L. Cullen Tales of the Ex-Tanks 269: I told him I hadn’t got around to the cracking game yet.
[US]G. Henderson Keys to Crookdom 402: Cracking. Breaking into a place or safe.

In compounds

cracking tools (n.)

(UK Und.) burglary tools.

[UK]E. de la Bédollière Londres et les Anglais 313/2: cracking tools, [...] outils brisants, qui servent à commettre le vol avec effraction.