This paper presents a study on the behavior under compression of three types of piles, built in the Experimental Field for Foundations and Soil Mechanics of the UNICAMP University. Three piles of each type were built: bored (without the use of bentonite slurry), continuous flight auger (CFA) and omega. Nominal diameters of the piles were 0.40 m, 0.40 m and 0.36 m, respectively, all of them 12 m in length. Local subsoil is characterized as a diabase type soil. The first layer (0 to 6 m) is a collapsible silty sandy clay, followed by clayey sandy silt (6 to 18 m). Water level is only reached at 17 m. The piles were instrumented along their depth with electric extensometers (strain gauges), installed at 0.30 m (section of reference), 5.0m, 11.1m and 11.7m. Instrument data indicated that all the piles behaved as friction piles: in average, the tip reaction reached 2% of the total applied load for the bored piles; 7% for the CFA piles and roughly 14% for the omega piles. In the same order, the mean ultimate load test values for the SML tests were 682kN, 885kN and 1,428kN.