Introduction

In construction projects, steel structures, factory installation, and industrial equipment assembly, connection bolts act as the “backbone” ensuring safety, stability, and load-bearing capacity of the entire system. The quality of bolts directly determines the durability and longevity of the project. Therefore, ing standard bolts with the correct strength grade is critically important in construction engineering.

Quoc Thinh Manufacturing Trading JSC is proud to be a reputable supplier of connection bolts – meeting standards, sufficient in quantity, competitively priced – serving contractors and projects nationwide.

Product Description

Connection bolts are manufactured from high-quality steel such as C45 or alloy steel, undergoing strict heat treatment processes to achieve strength grades from 4.6 – 5.6 – 8.8 – 10.9 – 12.9. Products can be electro-galvanized or hot-dip galvanized, enhancing oxidation and corrosion resistance in harsh environments. Both full-thread and partial-thread types are precisely machined according to DIN – ISO – JIS standards, suitable for all construction and mechanical connection requirements.

Technical Specifications – Grade 4.6 Bolts

• Standards: ISO / ASTM / EN / JIS / DIN

• Size: M8 – M22 or customized

• Length: As required

• Thread: Partial or full thread

• Material: CT3, C45 steel

• Strength Grade: 4.6

• Minimum Tensile Strength: 400 MPa

• Yield Strength: 240 MPa

• Origin: Quoc Thinh Vietnam, China

Technical Specifications – Grade 8.8 Bolts

• Standards: DIN 931, DIN 933, DIN 960, DIN 961, ISO

• Size: M10 – M24 or customized

• Length: As required

• Thread: Partial or full thread

• Material: Carbon steel

• Surface Finish: Black steel, electro-galvanized, hot-dip galvanized

• Origin: Quoc Thinh Vietnam, KPF Korea, KPF Vietnam, China

• Applications: Widely used in medium and heavy steel structures requiring high strength, such as pre-engineered steel buildings, steel frames, purlins, scaffolding, industrial machinery frames, M&E systems, bridge structures, flange connections, and mechanical equipment.

Outstanding Advantages

• High load capacity, suitable for heavy loads and strong vibrations.

• Superior tensile, compressive, and torsional strength due to standardized heat treatment.

• Anti-rust galvanization, especially hot-dip galvanized bolts for outdoor use.

• Sharp, precise threads for easy installation without slippage.

• Full range of sizes – large stock – always available.

Applications

• Construction of pre-engineered steel buildings, factories, warehouses.

• Assembly of beams, columns, purlins, trusses, steel frames.

• Installation of industrial equipment, tanks, conveyors, MEP systems.

• Infrastructure projects: bridges, power stations, heavy-load structures.

Usage Instructions / Notes

• Select the correct strength grade according to technical design documents.

• Use in combination with nuts and washers to enhance tightening and safety.

• Apply torque wrenches to achieve proper tightening torque.

• Periodically inspect bolts at high-load points.

Supplier & Policies

QUOC THINH MANUFACTURING TRADING JOINT STOCK COMPANY

✔ Capable of fulfilling large-volume orders

✔ Machining according to drawings and special requirements

✔ Competitive pricing for contractors, projects, and distributors

✔ Flexible sales policies, nationwide delivery

✔ Large warehouse – full range of sizes – fast dispatch

Contact for Consultation & Quotation

📞 Mr. Lam – +84 905 384 896 (Zalo)

📧 Email: tt.quocthinh1004@gmail.com