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

ISO4017 Bolt ISO4032 Nut ISO7089 Washer Set.png

Bolt Torque Decay Truth: Tight on Installation, Loose After One Week

2026-10-08

Aiming at the high-frequency engineering pain point that bolts are tight during installation but loose after one week of static operation, this article analyzes the three core mechanisms of torque decay: metal stress relaxation, gasket compression creep and joint surface settlement, distinguishes the essential difference between static invisible loosening and dynamic vibration loosening, summarizes foreign trade judgment disputes and construction pitfalls, and outputs standardized secondary locking and gasket optimization schemes, providing accurate anti-loosening assembly guidelines for overseas static equipment and steel structure projects.

2026-10-08

Bolt Blackening vs Bluing Process: Indoor & Outdoor Rust Prevention Misconceptions

2026-10-07

Aiming at the common foreign trade selection misconception that "blackened bolts have strong rust resistance", this article analyzes the essential process differences and anti-rust principles between bolt blackening and bluing, reveals the core reason for rapid outdoor rust failure of oxidation treatment, summarizes low-cost selection pitfalls such as blind cost reduction and confused indoor and outdoor working conditions, and sorts out standardized working condition adaptation and process replacement schemes, providing reliable selection basis for overseas fastener surface treatment procurement.

2026-10-07

Galvanized Color Difference: Bright Zinc / Black Zinc / Color Zinc Acceptance Standard

2026-10-06

Aiming at the high-frequency foreign trade pain points of galvanized fastener color difference complaints, appearance inconsistency and whole-order return disputes, this article defines the standard qualified appearance of bright zinc, black zinc and color zinc, distinguishes normal process color difference from defective unqualified color difference based on ISO and national standards, analyzes the core causes of batch deviation, visual misjudgment and transportation discoloration, and summarizes pre-order sample locking and batch quality control zero-dispute schemes, providing reliable acceptance basis and dispute avoidance guidelines for overseas galvanized fastener orders.

2026-10-06

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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

Bolt Torque Decay Truth: Tight on Installation, Loose After One Week

Bolt Blackening vs Bluing Process: Indoor & Outdoor Rust Prevention Misconceptions

Galvanized Color Difference: Bright Zinc / Black Zinc / Color Zinc Acceptance Standard

Get A Free Quate

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