Fasteners Manufacturers in South Korea | Exporters for Shipbuilding and Petrochemical EPC Procurement
South Korea is home to the world’s largest shipbuilding industry and one of Asia’s most concentrated petrochemical complexes, creating steady demand for correctly specified, fully documented industrial fasteners. Jade Alloys is a fasteners suppliers in South Korea partner trusted by EPC contractors, shipyard-approved fabricators, and industrial distributors serving Hyundai Heavy Industries (Ulsan), Samsung Heavy Industries (Geoje), and Hanwha Ocean (formerly Daewoo Shipbuilding, Geoje), supplying fasteners manufactured and tested at our own facility in Mumbai.
As an ISO 9001:2015 certified fasteners manufacturers in South Korea businesses turn to for both standard and specialist requirements, we supply the complete range of industrial fasteners in South Korea from workhorse hex bolts and heavy hex nuts for general shipyard and structural use, to precision stud bolts engineered for Yeosu and Ulsan petrochemical complex flanged joints. Every consignment ships with EN 10204 3.1 Mill Test Certificates and full heat-number traceability from our NABL-accredited in-house laboratory.
What separates Jade Alloys from South Korea-based re-exporters and regional trading houses is direct manufacturer access, no intermediary markups, full grade traceability, and the ability to manufacture to your exact drawing or project specification. Our Mumbai plant maintains a monthly production capacity exceeding 500 MT across all material grades, providing the production depth to fulfil both urgent site orders and long-lead bulk procurement contracts for bolts and nuts suppliers in South Korea clients.
For South Korean clients with GS Caltex, S-Oil, LG Chem, Lotte Chemical, or shipyard vendor requirements, we provide NACE MR0175 / ISO 15156 sour service documentation where required, third-party inspection via SGS, Bureau Veritas, or KR (Korean Register) coordination, and all export documentation required for clearance at Busan Port and Ulsan Port, including ISPM 15-compliant wood packing declarations.
Table of Contents:
- Specifications of Fasteners Supplied in South Korea
- Types of Fasteners We Supply in South Korea
- Bolt Dimension Chart
- Hex Nut Dimensions Chart
- Bolts and Nuts Suppliers & Manufacturers in South Korea
- Applications of Fasteners in South Korea
- Cities We Supply Fasteners in South Korea
- Countries We Export Fasteners
- Certifications & Quality Assurance
- Shipping Policy for Fasteners to South Korea
- Why Choose Jade Alloys as Your Fasteners Supplier in South Korea?
- Frequently Asked Questions — Fasteners Suppliers in South Korea
- Get a Quote from a Leading Fasteners Supplier in South Korea
Specifications of Fasteners Supplied in South Korea
Every fastener supplied by Jade Alloys to South Korea conforms to the specifications below. Contact us for custom dimensions or non-standard grades.
| Parameter | Details |
|---|---|
| Standards | ASTM, ISO, BS, ASME, DIN, and KS (Korean Industrial Standards) — dual-standard supply available |
| Fastener Length | 3 mm to 200 mm |
| Nuts Size | M3 – M56 | 3/16″ to 2″ | Custom Sizes |
| Bolt / Screw Size | M3 – M56 | 3/16″ to 2″ | Custom Sizes |
| Machine Screws Size | M1.6 – M12 |
| Washers Size | M3 – M56 | 3/16″ to 2″ | Custom Sizes |
| Stud Bolt Size | M6 – M100 | ¼″ to 4″ | Custom Sizes |
| Packing | Wooden pallet, small boxes / cartons / pallets, or as per customer request |
| Surface Finish | HDG, Zinc Plated, Zinc Flake, Black Oxide, Xylan, or as per customer request |
| Stainless Steel Grades | SS 304, 304L, 304H, 310, 316, 316L, 321, 321H, 347, 347H, 904L |
| Duplex Steel Grades | UNS S31803, S32205, S32550, S32750, S32760 |
| Alloy / Carbon Steel Grades | ASTM A193 B7, B16, B8, B8M; ASTM A307, A325, A453 Gr 660 |
| Nickel Alloy Grades | Monel 400, Inconel 600, 625, 718, 825, Hastelloy C-276, C-22 |
Types of Fasteners We Supply in South Korea
Jade Alloys stocks and exports the full spectrum of fastener types to clients across South Korea. As one of the leading bolts and nuts suppliers in South Korea, every product is backed by MTR and third-party inspection. Explore our product pages for detailed specifications:
Bolt Dimension Chart
The table below covers the most common bolt sizes supplied to South Korea. Custom sizes are available on request.
| Nominal Size | Bolt Diameter Max (in) | Bolt Diameter Min (in) | Across Flats (in) | Head Height (in) | Thread Length ≤6in |
|---|---|---|---|---|---|
| 1/4 | 0.250 | 0.245 | 7/16 | 5/32 | 0.75 |
| 5/16 | 0.3125 | 0.3065 | 1/2 | 13/64 | 0.875 |
| 3/8 | 0.375 | 0.369 | 9/16 | 15/64 | 1.00 |
| 7/16 | 0.4375 | 0.4305 | 5/8 | 9/32 | 1.125 |
| 1/2 | 0.500 | 0.493 | 3/4 | 5/16 | 1.25 |
| 5/8 | 0.625 | 0.617 | 15/16 | 25/64 | 1.50 |
| 3/4 | 0.750 | 0.741 | 1-1/8 | 15/32 | 1.75 |
| 7/8 | 0.875 | 0.866 | 1-5/16 | 35/64 | 2.00 |
| 1 | 1.000 | 0.990 | 1-1/2 | 39/64 | 2.25 |
| 1-1/4 | 1.250 | 1.239 | 1-7/8 | 25/32 | 2.75 |
| 1-1/2 | 1.500 | 1.488 | 2-1/4 | 1-5/16 | 3.25 |
For full metric ranges and weight-per-piece figures, see the Bolts Weight Chart, or calculate custom sizes with our Metal Weights Calculator.
Hex Nut Dimensions Chart
Standard hex nut dimensions for all sizes supplied to South Korea clients. Contact us for heavy hex, nylock, and specialty nut dimensions.
| Size | Nominal Diameter (in) | Width Across Flats – Nominal (in) | Width Across Flats – Min (in) | Thickness Min (in) | Thickness Max (in) |
|---|---|---|---|---|---|
| #0 | 0.060 | 5/32 | 0.150 | 0.043 | 0.050 |
| #4 | 0.112 | 1/4 | 0.241 | 0.087 | 0.098 |
| #8 | 0.164 | 11/32 | 0.332 | 0.117 | 0.130 |
| 1/4″ | 0.250 | 7/16 | 0.423 | 0.178 | 0.193 |
| 5/16″ | 0.312 | 9/16 | 0.545 | 0.208 | 0.225 |
| 3/8″ | 0.375 | 5/8 | 0.607 | 0.239 | 0.257 |
| 1/2″ | 0.500 | 3/4 | 0.736 | 0.283 | 0.302 |
| 3/4″ | 0.750 | 1-1/8 | 1.100 | 0.441 | 0.464 |
| 1″ | 1.000 | 1-1/2 | 1.469 | 0.563 | 0.591 |
Full nut weight-per-piece data across all sizes is available on the Nuts Weight Chart, and dimensions for matching bolts sit on the Bolts Weight Chart.
Bolts and Nuts Suppliers & Manufacturers in South Korea
As certified bolts and nuts suppliers in South Korea, Jade Alloys carries a comprehensive range of ASTM-standard bolts and nuts. Browse our product ranges below:
Nuts Product Range (ASTM Standards)
Shipyard & Petrochemical Project Compliance: Jade Alloys manufactures fasteners suitable for Hyundai Heavy Industries, Samsung Heavy Industries, Hanwha Ocean, GS Caltex, S-Oil, and LG Chem material specifications, including NACE MR0175 / ISO 15156 requirements for sour service environments. Third-party inspection via SGS, Bureau Veritas, or KR (Korean Register) coordination can be arranged for formal vendor submission.
Applications of Fasteners in South Korea
Our fasteners in South Korea are trusted by the most demanding sectors in the country:
- Shipbuilding & Marine: Hyundai Heavy Industries (Ulsan), Samsung Heavy Industries (Geoje), Hanwha Ocean (Geoje) commercial vessels, LNG carriers, offshore structures
- Petrochemical & Refining: GS Caltex and S-Oil (Yeosu/Ulsan refineries), LG Chem and Lotte Chemical petrochemical complexes
- Steel & Heavy Industry: POSCO steelworks (Pohang and Gwangyang), heavy engineering and forging
- Semiconductor & Electronics: Samsung Electronics and SK Hynix fabrication facilities (Icheon, Pyeongtaek)
- Offshore & Marine Engineering: Offshore platform fabrication, FPSO and drillship construction
- Power Generation: Coal, LNG, and nuclear power plant construction and maintenance
- Construction & Infrastructure: Seoul and Busan commercial and infrastructure development
- Engineering & Heavy Equipment: Industrial fabrication shops across Changwon and the greater Busan-Ulsan industrial corridor
Cities We Supply Fasteners in South Korea
Jade Alloys distributes fasteners in South Korea across every major industrial hub and city:
| City / Region | Key Industries |
|---|---|
| Busan | Primary sea freight entry; port logistics, shipbuilding support industries |
| Ulsan | Hyundai Heavy Industries shipyard; petrochemical refining (GS Caltex, S-Oil) |
| Geoje | Samsung Heavy Industries and Hanwha Ocean shipyards; offshore fabrication |
| Yeosu | Petrochemical complex; GS Caltex, LG Chem, Lotte Chemical |
| Pohang | POSCO steelworks; heavy engineering |
| Gwangyang | POSCO integrated steelworks; port logistics |
| Changwon | Heavy machinery, defence, and industrial equipment manufacturing |
| Incheon | Port and airport logistics hub; manufacturing and distribution |
| Seoul / Gyeonggi Province | Industrial distribution, EPC contractors, MRO procurement |
| Icheon / Pyeongtaek | Samsung Electronics and SK Hynix semiconductor fabrication |
Countries We Export Fasteners
Beyond South Korea, Jade Alloys exports fasteners and bolts and nuts to major markets worldwide, with the same ISO 9001:2015 quality system and full documentation that backs every shipment to our fasteners suppliers in South Korea clients.
Frequently Asked Questions — Fasteners Suppliers in South Korea
Jade Alloys is an ISO 9001:2015 certified fasteners supplier in South Korea, manufacturing bolts, nuts, and stud bolts to ASTM, ISO, and KS standards for EPC contractors and industrial buyers supplying Hyundai Heavy Industries, Samsung Heavy Industries, Hanwha Ocean, and Yeosu/Ulsan petrochemical complexes. Every shipment ships with EN 10204 3.1 Mill Test Certificates.
Jade Alloys is a direct manufacturer of industrial fasteners based in Mumbai, India, not a trading company. Buying directly eliminates middlemen, keeps quality consistent, and delivers better pricing for fasteners manufacturers and suppliers comparisons across South Korea.
Jade Alloys supplies fasteners suitable for Hyundai Heavy Industries (Ulsan), Samsung Heavy Industries (Geoje), and Hanwha Ocean shipyard projects, with third-party inspection available on request via SGS, Bureau Veritas, or Korean Register (KR) coordination to support formal vendor submissions.
Fasteners manufacturers supplying South Korea, including Jade Alloys, typically stock stainless steel grades (SS 304, 304L, 316, 316L, 321, 347, 904L), duplex steel (UNS S31803, S32205, S32750, S32760), and nickel alloys such as Inconel 600/625/718, Monel 400, and Hastelloy C-276, alongside carbon and alloy steel for standard structural bolting.
Sea freight transit from Mumbai to Busan Port typically takes 14–18 days, and to Ulsan Port 15–19 days, with stocked items dispatched within 3–5 business days. Air freight to Incheon International Airport is available for urgent requirements in 3–5 days.
Jade Alloys supplies fasteners suitable for GS Caltex, S-Oil, LG Chem, and Lotte Chemical facilities across the Yeosu and Ulsan petrochemical complexes, including NACE MR0175 / ISO 15156 sour-service grades where required.
Buyers sourcing fasteners for South Korea shipbuilding, petrochemical, or power projects should confirm ISO 9001:2015 quality certification, EN 10204 3.1 Mill Test Certificates with heat-number traceability, NABL-accredited lab testing, and NACE MR0175 / ISO 15156 compliance for sour-service grades. Jade Alloys holds all four.
Yes, Jade Alloys manufactures custom sizes, special lengths, and non-standard fasteners to a buyer's drawings and specifications, with sizes ranging from M3 to M100 for stud bolts and up to 4 inches in imperial.
Get a Quote from a Leading Fasteners Supplier in South Korea
Source fasteners in South Korea with confidence through Jade Alloys, a certified and reliable manufacturer. We guarantee quality products, proper documentation, and fast turnaround times. Submit your RFQ including material grade, quantity, and delivery location, and our team will revert within 24 business hours.

