The first company producing Bolt & Nut in Korea In 1961, Our company Dongah started producing high strength bolt of friction type used in steel bridges and steel structures for the first time in Yeongdeungpo plant, Korea and transferred Bupyeong plant. After that, we relocated to Changwon Plant and were established factory automation with more modern facilities. In 1993. We developed Torque control bolt and certified our quality through being held presentation&test. Now, it's used in many construction sites. Accumulated technology for 50 years We were designated as Heat treatment certification company from global company, Komatsu with 50 years of accumulated technology and know-how about track bolts special process. Dongah monopolized our goods in Korea and is getting grow export market to United States, Japan, East Asia Furthermore, we are trying to produce the best bolts&nuts using best quality system to repay for customers. Takeoff to global company Dongah provides best service to customers in heavy equipment and industrial part with the newest skill. We will create value for customers and committed to corporate social responsibility for growing up to global company