Rotary tool

A tool for friction stir welding used in friction stir welding processing, wherein

• said tool for friction stir welding includes a base material and a coating layer formed on the base material,
• said base material includes a first hard phase, a second hard phase and a binder phase,
• said first hard phase is formed by WC particles,
• said second hard phase is formed by a compound of one or more metals selected from the group consisting of Ti, Zr, Hf, Nb, Ta, Cr, Mo, and W and one or more elements selected from the group consisting of nitrogen, carbon, boron, and oxygen, or a solid solution of the compound (except for WC), and is included in said base material at a volume ratio of 3% by volume or more and 30% by volume or less,
• said binder phase is formed by an iron group metal and is included in said base material at a volume ratio of 8% by volume or more and 28% by volume or less, and
• a constituting ratio between said first hard phase and said second hard phase is such that said first hard phase is higher than said second hard phase in terms of volume ratio,
• wherein the coating layer comprises an Al0.6Ti0.35Si0.05N layer, or a Ti0.5Al0.5N layer and an Al0.7Cr0.3N layer alternately stacked.