S.P. Metalwork Co., Ltd. was registered and established on January 13, 1995 by Mr. Sompong Phongkriangyot to operate a metal casting business, such as gray cast iron, ductile cast iron, cast ductile iron, and special cast iron, etc., focusing on production according to customer needs (OEM) before expanding the business to produce various types of cast iron equipment, plumbing pipes, and cast iron water gates under the SP trademark as seen today.