The use of friction stir welding techniques to join high-strength materials such as steel and tungsten alloys faces a major problem in terms of tool life and tool cost due to high wear. In the present work, a cost-efficient WC-11%Co tool and a novel composite of WC-11% Co+ 1% carbon nanotubes (CNT) tools are manufactured to achieve the tool wear solution. For this purpose, at first pre-sintering temperature and holding time were calculated. Sintering of various compacted tools are sintered at 850 °C to 1300 °C with holding times varying from 30 to 1500 min, whereas four attempts were made to manufacture FSW tool at 850 °C, 950 °C, 1050 °C, and 1300 °C. A comparative study of 11% cobalt tools with added CNT particles was performed. Higher compaction density, higher holding time, more homogeneous mixture of raw materials, good proportionate of organic binder, and temperature between 1050 °C and 1300 °C, with cobalt percentage in between 11%, produce the finest tools. Joining of carbon-manganese steel with high-strength FSW tool performed very smoothly.