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This research studies pass numbers effect on microstructure and mechanical properties of magnesium alloy of AZ31C in the tubular channel angular pressing (TCAP) at the temperature of 300 °C. Pressing process has been carried out through four pass over AZ31C Magnesium tubes and in each pass the sample is exposed to Tensile and microhardness test and Metallography. The microstructure and mechanical properties of processed tube through one to four passes of TCAP process were investigated. Microhardness of the processed tube was increased to 62Hv after one pass from an initial value of 55 Hv. An increase in the number of passes from 1 to higher number of passes has not more effect on the microhardness. Yield and ultimate strengths were increased 1.97 and 1.49 times compared to as cast condition. Notably increase in the strength was achieved after two pass TCAP while higher number of passes has not more effect. Microstructural investigation shows notably decrease in the grain size to around 6 µm from the primary value of ~200 µm. microscope images show that the grain size is getting smaller by the first pass buy bigger in the next passes.