Hwashin Bolt Industry has fully localized the production of large-scale high-temperature and high-pressure bolts used to fasten split steam and gas turbine casings. These products are applied to global turbine models manufactured by General Electric, Siemens, and Mitsubishi Heavy Industries, and are reliably supplied to domestic power plants. By eliminating import dependency, we significantly reduce maintenance costs and lead times. Supplied items include THRU STUD, TAP STUD, COUPLING SET, and DOWEL PIN.

Key Role of Turbine Casing Bolts

Turbine casings are horizontally split structures joined by large horizontal bolts. Under extreme operating conditions of 550–650°C and steam pressures up to 150 bar, these bolts must simultaneously maintain airtight sealing, structural rigidity, and vibration resistance. Even a single leakage is unacceptable, making them critical safety components. The localization of turbine casing bolts strengthens technological independence in Korea’s power generation industry and enhances global competitiveness in high-temperature and high-pressure fastening solutions.

Hwashin Bolt Industry has fully localized large high-temperature nuts used to fasten steam and gas turbine casings. These products are applied to turbine models from GE, Siemens, and Mitsubishi Heavy Industries, and are stably supplied to domestic power plants. By replacing imported products, we significantly reduce maintenance costs and lead times. Supplied items include SLOTTED NUT, COVERED NUT, and ROUND NUT.

Key Role of Turbine Casing Nuts

Turbine casings are divided into upper and lower flanges across HP (High Pressure), IP (Intermediate Pressure), and LP (Low Pressure) stages, fastened with large stud bolts and nuts. Operating in extreme environments of 500–600°C and pressures exceeding 100 bar, these nuts must ensure sealing integrity and balanced thermal expansion. Designed for frequent disassembly and reassembly during scheduled overhauls, slotted nuts (key/wire locking type) and covered nuts (dust and heat protection type) maximize torque control and durability. The localization of turbine casing nuts ensures stable plant operation and economic efficiency while strengthening competitiveness in high-temperature fastening technology.

Hwashin Bolt Industry supplies piping bolts for offshore plant systems (FPSO, F-LNG, Drillship, Jack-up Rig, Semisubmersible, Submarine, etc.) to leading domestic EPC companies, providing long-term support for high-specification projects.

Hwashin’s Piping Bolt Technology

Supplied products include Stud Bolts, Heavy Hex Bolts, Nuts, Washers, and U-Bolts using marine-grade materials such as ASTM A320 L7 and B7M, with Xylan coating available.

Proven Performance

Long-term supply of submarine propulsion piping systems and F-LNG topside piping stud bolt sets to Samsung and Hyundai demonstrates our reliability. Piping bolts are critical fastening components that directly impact offshore plant safety and performance, supported by Hwashin’s advanced Xylan coating technology.

Hwashin Bolt Industry manufactures and supplies precision 12-point bolts that deliver superior fastening performance in high-tensile and high-fatigue environments. With twice the contact surface area of conventional hex bolts, they ensure stable high-torque fastening even in confined spaces.

Hwashin’s 12-Point Bolt Technology

Manufactured from high-strength materials such as ASTM A193 B7 and Inconel, compatible with API 20E specifications, these bolts undergo specialized heat treatment followed by Zinc-Nickel or TEFLON coating for optimal corrosion and friction control. Precise tolerance management of the 12-point head ensures uniform fastening force without head damage under maximum torque. Custom production is available to meet specific shank tolerances and drill-hole requirements. 12-point bolts are critical fastening components in high-torque and space-restricted applications, ensuring safety and reliability through Hwashin’s precision engineering.

Hwashin Bolt Industry manufactures and supplies high-strength, high-precision compressor rotor bolts used to secure high-speed rotors in centrifugal and screw compressors, supporting stable operations across plants, shipbuilding, and power generation industries.

Compressor Rotor Bolt Technology

Using API 20E high-strength alloy steels such as ASTM A193 B7 with specialized heat treatment, these bolts are optimized for anti-loosening performance and fatigue strength under extreme rotational speeds. Precision machining within ±0.1 mm tolerance, specialized thread geometry for uniform torque distribution and preload management, and custom production based on rotor dimensions—including length, diameter, and UN thread specifications—are available. Compressor rotor bolts are critical safety components during overhauls and new installations, ensuring long-term stable operation.

Hwashin Bolt Industry precisely supplies Bonnet Bolts optimized for high-pressure equipment such as Cameron Subsea and drilling systems in compliance with API 20E specifications. These bolts serve as critical fastening components for flange connections and drilling module assembly.

Key Role of Bonnet Bolts

Featuring a double-ended threaded structure, bonnet bolts are specifically designed for high-pressure flanges (wellhead BOP, Christmas Tree, and high-pressure modules) that require frequent disassembly and reassembly. They maintain stable clamping force even under high-temperature and high-pressure environments.

Hwashin Bolt Industry’s Bonnet Bolt Technology

High-strength alloy steel materials are processed with API 20E-compliant heat treatment to ensure durability under extreme conditions. Precision grinding of special thread profiles, including thread relief and taper machining, guarantees dimensional accuracy. Customized single-order production enables immediate response to client-specific specifications. As essential components directly related to safety—such as wellhead BOPs, Christmas Trees, and high-pressure flange connections—Hwashin’s bonnet bolts are backed by rigorous quality control and API-certified technology, ensuring the highest level of reliability.