STP&I Public Company Limited was established in 1975, with over 42 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 ChonburiandRayong, Piping fabrication shop in Sriracha and Assembly yard at LaemChabang Port. With a total capacity of115,000 ton /year,STP&Ihasused its capacity at 40 %in year 2016.

STP&I Public Company Limited has foursubsidiaries, STIT Co., Ltd (“STIT”) STP&I Services Co., Ltd. (“STPS”), STIT 2011 Co., Ltd. (“STIT2011”), and WPGE Phetchaburi Co., Ltd. (“WPP”)which is owned by STIT Company Limitedwith 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


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


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

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 Companyprovides 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.

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 inboth 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 Fabrication Steel: The Company has provided other Fabrication steel such as pressure vessel work includes drum, reactor, columns, splitter towers, stream drums, and separators.

STP&I places great importance in producing high quality and maintaining high standards of all its products. The Company follows stringent quality-controlmanagement 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 : 2008 – 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