Union Autoparts Manufacturing Co., Ltd (UAM) is a member of the distinguished Okaya & Co. Ltd group of companies in Japan and Siam Steel Group. It is one of the leading manufacturers of high-quality steel rims and spokes for motorcycles worldwide.

Union is the main supplier to most motorcycle factories in Southeast Asia.

• Thai Honda Manufacturing Co., Ltd
• Thai Yamaha Motor Co., Ltd
• Thai Suzuki Motor Co., Ltd
• Kawasaki Motors Enterprise (Thailand)
• Honda Motor Co., Ltd., Japan
• Yamaha Motor, Ltd., Japan
• Yamaha Motor Sdn. Bhd., Malaysia
• MODENAS, Malaysia
• Honda Philippines Inc., Philippines
• Kawasaki Philippines Inc., Philippines
• Suzuki Philippines Inc., Philippines
• Kawasaki Motor, Indonesia
• PT Yamaha Indonesia Motor
• Yamaha Motor, Taiwan
• Yamaha Motor Asia Pte. Ltd., Singapore
• Honda Turkey
• Iran Kawasaki