STP&I Public Company Limited was established in 1975, with over 43 years of experience, the Company has provided customers with professional manufacturing of customized quality steel fabrication including Steel Structure, Piping Fabrication, Process Module, and Other Fabrication steels such as Modules, Tank, Pressure Vessel, and Boiler. One of STP&I’s strengths is its capability to fabricate large built-up beam steel for huge infrastructure and heavy industry projects such as power plants, refineries, high-rise buildings, roof structures, bridges, elevated highways, and airports.

STP&I owns and operates four production plants include Steel Structure fabrication plants in Chonburi and Rayong, Piping fabrication shop in Sriracha and Assembly yard at Laem Chabang Port. With a total capacity of 115,000 ton /year,STP&I has used its capacity at 8% in year 2017.

STP&I Public Company Limited has five subsidiaries, STIT Co., Ltd ("STIT") STP&I Services Co., Ltd. ("STPS"),ST Property & Logistics Co., Ltd. ("STPL"),STIT 2011 Co., Ltd. (“STIT2011”) which is owned by STIT Co., Ltd., and WPGE Phetchaburi Co., Ltd. ("WPP") which is owned by STP&I Services Co.,Ltd. with the following details;

Company Name Type of Business Paid-up Capital
% of Shares Held by STP&I
STIT Co., Ltd. Sales and rental of machinery and equipment for construction and manufacturing industries 135,000,000 100
STP&I Services Co., Ltd. Construction Services 410,000,000 100
STIT 2011 Co., Ltd. Sales and rental of machinery and equipment for construction industry 66,033,000 100
WPGE Phetchaburi Co., Ltd. Operate a municipal solid waste power plant (waste to energy) 700,000,000 60
ST Property & Logistics Co., Ltd. Logistic and Property Development 700,000,000 100


STP&I strongly engages in mega steel construction for construction business including machinery and equipment for construction business.


To be a leader in steel construction module for export especially in energy sector and to continue sustainability growth which create value added to all parties.

Corporate Objective / Goal

To be a leader in hi-technology steel construction for mage project around the world with all-time competitiveness and development.

  1. To satisfy customer on production aspect;
    (a) Standardized quality of products
    (b) On time delivery
    (c) Budget control
    (d) Without loss time injury
    (e) Strong and continued relationship with the old customer
  2. Sustainable growth by seeking new opportunities that has strong growth and continuously generated income such as renewable energy industry and property development and logistics.


The Company strategy for sustainable growth are as follows:

  1. Concentrated on customer satisfaction, on-time delivery, and minimize on Loss Time Injury
  2. Efficient management and people
  3. Maintain strong financial position and management
  4. Seeking new businesses that continuously generated income growing business growth renewable energy industry and property development and logistics

Core Business of STP&I can be categorised into three key groups:

  1. Engineering Service: The Company provides engineering service in detail design of steel-to-steel connection, shop drawing for steel structure, piping, and erection works by various specialized software.

  2. Fabrication: The Company provides fabrication service and has the capability to fabricate steel and pipe in workshop which equipped with state of the art machine and equipment, CNC Cutting and Welding machine, Press machine, automatic Blasting machine and other tools necessary to undertake the variety and complexity of fabricated products to ensure the efficiency of fabrication processes and cost effective.

  3. Construction: STP&I’s construction works include assembly, mechanical equipment installation and erection for various manufacturing plants. The Company performs the works both at the Company’s facilities and at the client’s project site.
  4. Decommissioning & Dismantling: The company provides service of demolishing all kinds of constructions including demolishing constructions in sea, on land, pipe lines, petroleum storage, facilities, equipment and other material used for exploring, manufacturing, maintaining, transporting, selling or distributing petroleum.

Company Products can be categorized into 4 groups.:

  1. Steel Structure Fabrication
    1. Steel structures for heavy industrial such as gas separation plant, power plant, refinery, petrochemical plant, etc.
    2. Steel Structure for building such as high – rise building, airport terminal.
    3. Steel Structure for infrastructure system such as bridge,elevated road, airport, etc.
  2. Piping Fabrication: STP&I has expertise in piping fabrication which includes piping pre-fabrication, piping erection, and pipeline constructions. The spoon fabrication is carried out in STP&I’s facilities, then the semi - completed products are transported to the project sites for installation. These pipes are essential parts in the production process of industrial plants such as power plants, oil refineries, petrochemical plants, offshore process plants, etc.

  3. Process Module: STP&I expands its business to Process Module assembly. Module is a large system structure comprises steel structure, piping system, boiler, pressure vessels, machinery, electrical system and controlling system for various industries. Module mostly used in both onshore and offshore construction such as oil and gas platform or large projects that have limitation on working area or labor or time constraint.

  4. Other Steelwork: The Company also fabricates other steelwork such as Pressure Vessel, Tank, Boiler and HRSGs by considering size of the project, schedule, availability of production capacity, machine efficiency, experiences and expertise of the personnel in each type of product.

STP&I places great importance in producing high quality and maintaining high standards of all its products. The Company follows stringent quality-control management practices as per international standards. And also, the Company realized that the commitment to the community on the safety of our products in various projects such as bridges, terminal buildings, and industrial plants. As such, STP&I has obtained accredited certifications from numerous internationally recognized institutions including:

  1. ISO 9001 : 2015 – The Manufacture of Structural Steel and Piping Work (Excluding Design)
  2. JSA Grade "H" (Japan Steel Structure Appraisal Center Limited) for Structural Steel Work for export to Japan.
  3. ISO3834-2: 2013 – Pipe Welding
  4. OHSAS 18001 : 2007 Occupational health and safety
  5. ISO 14001 : 2015 Environmental Management

The Company delivers only high quality products and services, thus, it has fully earned trust from its customers and has established a world-class status in the market. STP&I always give priority to both quality products and operational safety to which the Company will continue to invest in these two critical areas to even better serve both its domestic and overseas customers by increasing safety practices and ensuring all products are of exceptional quality. The Company has targeted to continuously compete with the highest record of accident free operation.