The use of TWB has been developed in automotive industries because of it’s advantages such as reduction in weight, cost and fuel economy of vehicles. The main objective of the peresent work is to study the effects of weld zone, diffrence in surface coating and thickness ratio on the formability of TWB composed of AISI 304, SPCC and IF steel sheets. It was found that the narrow weld zone has little effect on the formability of TWB. Results of LDH testing of TWB reveals the formability of TWB decrease as the thickness ratio of sheet increases. Fracture in LDH testing of TWB that composed of steel sheets with different surface coating occured on uncoated sheet because of changing in surface friction conditions. Manuscript profile