Theta Tau was founded as the Society of Hammer and Tongs on October 15, 1904 by Erich Julius Schrader, Elwin Leroy Vinal, William Murray Lewis, and Isaac Baker Hanks, each of whom were mining engineering students at the University of Minnesota. They agreed that character qualifications should have top priority in membership selection.
The Fraternity fulfilled the dream of its principal founder, Erich Schrader, that there be established in engineering a fraternity similar to those already existing in law, medicine, and dentistry. Schrader established a record of service unequaled in the fraternity's history. He served as its first grand regent until 1919, and then for thirty-five years as the grand scribe. At its Founders' Golden Anniversary Convention (1954), Theta Tau established the position of counselor to be held only by him. His unselfish service continued until his death in 1962, at the age of 81. The other founders also maintained their interest in the Fraternity throughout their lives. The last, Brother Vinal, died in 1971.
Brother Schrader was chiefly responsible for the Ritual, Constitution, and the Bylaws adopted by the founders. The first badge was a gold skull with the letters Θ and Τ on its forehead, and a crossed hammer and tongs beneath. The Constitution provided for the establishment of additional chapters at other leading engineering schools, and the fraternity soon began to take on its national character. Brother Hanks spoke of Theta Tau to his friend Robert Downing, a member of the Rhombohedron Club at Michigan College of Mines. After correspondence and an inspection trip by Brother Hanks, the club (established in 1903) was installed as Beta Chapter in 1906.
The oldest symbol of the fraternity still in use is the coat of arms adopted in 1906. It may only be displayed or worn by members.
Founder Lewis transferred to the Colorado School of Mines and there made contact with the Square Set Club which became Gamma Chapter in 1907. The Southwestern Alumni Association, the fraternity's first, was established in Douglas, Arizona in 1908.
In 1911, representatives of the three chapters and the alumni association met at the University of Minnesota for the first national convention, the name was changed to Theta Tau, a revised ritual was approved, and the present badge was adopted. Perhaps most important for its future expansion, it was decided that Theta Tau would include all branches of engineering.
At the 1976 National Convention, the Fraternity adopted a plan that opened up membership to women, with Delta Chapter at Case Western Reserve University being one of the first Theta Tau chapters to implement the plan in 1977. Mu Chapter initiated its first female members in 1985.
Since the turn of the millennium, the Fraternity has been experiencing record growth nationwide. In 2004, Theta Tau celebrated its centennial; at that point in time, more than thirty-thousand members had been initiated. Since 2010 alone, the Fraternity has installed more than twenty new chapters, and many additional colonies have been certified.