They were taken from the yard of AMD in Newton Road sometime around 10.45 pm last Thursday night after the security gate was breached.
The grey coloured rock breakers are valued at £5000 each.
Around the same time a second break in happened at the adjoining premises of JG Findlay in Old Irongray Road.
A number of new hedge trimmers are thought to have been stolen there and a full stock check is now being carried out to determine the exact details of the stolen property.
Police are investigating and Detective Constable Ryan Kirk said: “It appears that these thefts may be linked as the premises sit next to each other, and the timings are the same.
“We are keen to trace a white or silver coloured van which was seen in the Newton Road area at around 10.45 pm on Thursday night and which contained three men in dark coloured clothing.”
Anyone who may have been in the area and who saw anything suspicious is asked to call police at Dumfries on the 101 number.