The official Twitter home of SMART — the International Association of Sheet Metal, Air, Rail and Transportation Workers. The International Association of Sheet Metal Air Rail and Transportation Workers serves to protect and raise the living standards of over 230,000 skilled men and women employed throughout the United States and Canada. SMART the International Association of Sheet Metal Air Rail and Transportation Workers is one of North America's most dynamic and diverse unions with 203,000 members. SMART's members ensure the quality of the air we breathe promote energy efficiency produce and provide the vital services that move products to market and passengers to their destinations. We are sheet metal workers service technicians bus operators engineers conductors sign workers welders production employees and more. With members in scores of different occupations we advocate for fairness in the workplace excellence at work and opportunity for all working families.