HEX BOLTS

The products are strictly conform with DIN, ISO, ASTM, ANSI, BS, JIS...

● Level: A325/A325M/A490/A490M/8.8 /10.9/12.9/Gr5/Gr8

● Coating: Plain/Black/Galvanized/H.D.G /YZP/Dacromet/Xylan

ASTM B7/B7M

THREAD RODS

The longest can reach 3.66 meters(12FT)

China Professional Metal Fasteners

Manufacturer and Supplier with Over 20 Years of Experience

Bolt

Head shape: Hexagonal head, square head, round head can all be produced.
Size: M4-M100, 3/8 "-4"...

Nut

Type: hex nut, cap nut, couple nut, lock nut, spring nut
Size: M4-M100, 3/8'-4' is divided...

Washer

Type: Flat washer, spring washer
Specifications: M3-M100, 1/4

Threaded Rod

Size: M4-M100, 3/8 "-4", divided into metric size and inch size
Thread type: Full Thread

Precast Accessories

Size: Customization based on drawings or samples, both metric size and inch size are available

Custom Fasteners

Size: Customization based on drawings or samples, both metric size and inch size are available

About Material

Carbon steel, alloy steel, stainless steel are all acceptable.
According to customer requirements

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Topbolt - Best Standard Bolts and Nuts for Your Industries

The products are applied to architectural steel structures, brigdes, oil, pipeline, machinery equipment, furniture, vessel, railway.

Bridge
Industry
Ship
Solar Power
Steel Structural

Why Choose Topbolt for Your Projects?

Trusted Supplier of Bolts, Nuts, and Fasteners Conforming to DIN, ANSI/IFI, JIS, BS, ISO, and GB Specifications.

Ningbo Topbolt Metalworks Co., Ltd. is a manufacturer in China which mainly produces high strength fasteners and specializes in all kinds of hardwares. Founded in 2001, In the past few years, it developed fast with its factory located in Ningbo Zhenhai Chemical industrial area and its headquarter /foreign sales department in Ningbo Jiangdong Eastern Business Centre.

The factory now covers an area of approximately 15,000 square meters, with monthly production capacity of 2000 tons. The company has its all-around research system, supply management, large-scale warehouse...

Founded In

㎡

Covers an Area

Monthly Production Capacity

million

Annual Sales

DIGITAL SHOWROOM

If you want to learn more about our manufacturing capabilities, you can click on the avatar in the scene, or accept my invitation!

What Makes Topbolt Fasteners Manufacturing Stand Out?

Material Science

Carbon steel, alloy steel, stainless steel, Special material customization
Direct procurement from raw material factories, discounted prices, and sufficient stock availability

Standard

Strictly produce according to standard dimensions such as DIN, ISO, GB, JIS, ASTM, SAE, ASME, etc

Services

Accept customized production (including sample processing, drawing processing), OEM production

Topbolt News & Fasteners Knowledge Center

Full-Thread Stud Selection Guide: Sagging, Vibration Offset & Deformation Risks

2026-09-30

Aiming at the common rework pain points of ultra-long full-thread studs in overseas steel structure hoisting and equipment support projects, such as self-weight sagging, bending deformation and vibration offset instability, this article analyzes the rigid failure mechanism of over-limit length-diameter ratio, compares the safety boundaries of different specification matching, summarizes foreign trade customization and construction high-frequency pitfalls, and sorts out standardized length control and reinforcement schemes, providing accurate and anti-rework full-thread stud selection guidelines for overseas engineering projects.

2026-09-30

High-Strength Bolt Preload Misconception: Tighter Does Not Mean Safer

2026-09-29

Aiming at the common construction misconception of "the tighter the bolt, the safer" in overseas high-strength bolt assembly projects, this article analyzes the failure mechanism of tensile elongation and brittle head burst caused by excessive preload, compares the stress differences of insufficient, standard and over-locking states, summarizes on-site high-frequency wrong operation pitfalls, and sorts out international standard preload torque control rules, providing safe and standardized assembly guidelines for overseas steel structure and mechanical equipment projects.

2026-09-29

What Does A Flat Washer Do in A Bolted Joint?

2026-09-30

Tightening a bolt creates concentrated pressure beneath the head or nut. That small contact area can affect the entire joint. A flat washer sits between the fastener and the joint surface. It increases the bearing area and reduces local surface pressure. It can also protect the material and create a more stable seating surface. These effects may reduce indentation, embedment, and unwanted preload loss. However, a standard flat washer should not be treated as an anti-loosening device. Here, you will learn when a washer matters, where it should be placed, and how diameter, thickness, and hardness affect bolted joint performance.

2026-09-30

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We welcome all of you from all over the world to join us for the win-win business partnership and friendship, welcome to China, welcome to Ningbo Topbolt!

China Professional Metal Fasteners

Topbolt - Best Standard Bolts and Nuts for Your Industries

Why Choose Topbolt for Your Projects?

DIGITAL SHOWROOM

Full-Thread Stud Selection Guide: Sagging, Vibration Offset & Deformation Risks

High-Strength Bolt Preload Misconception: Tighter Does Not Mean Safer

What Does A Flat Washer Do in A Bolted Joint?

Get A Free Quate

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