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

Flange Bolt Selection: Why Plain Washers Cannot Replace Integral Flange Face

2026-11-05

Flange bolts are widely used in equipment assembly and maintenance. Many overseas maintenance engineers tend to replace flange bolts with ordinary bolts plus separate plain washers. This replacement will lead to insufficient contact area, uneven pressure distribution, seal failure and loosening risk. This article explains the structural characteristics of flange bolts, the failure causes of wrong substitution and correct selection principles, taking **DIN6921** flange bolts as the reference.

2026-11-05

Fastener Surface Treatment Comparison: Zinc Plating / Dacromet / HDG / Mechanical Galvanizing

2026-11-04

Surface treatment is a key factor affecting fastener corrosion resistance and service life. Many overseas buyers cannot tell the differences between electro zinc plating, dacromet coating, hot dip galvanizing and mechanical galvanizing, and often select the wrong coating for outdoor or marine environments. This article compares four common surface treatments on thickness, salt spray performance, thread interference, cost and suitable scenarios, helping buyers make correct selection for different working conditions.

2026-11-04

J-type Foundation Anchor Bolt Hot-dip Galvanized J-hook Embedded Bolt for Construction Base.png

Anchor Bolt Embedding Deviation: Positioning Error Causes Steel Structure Alignment Failure

2026-11-03

Anchor bolt embedding deviation is a common problem in overseas civil and steel structure projects. Incorrect positioning during pre-embedding will lead to failed alignment when hoisting steel members, requiring secondary reaming or other rectification work. It brings extra cost and delays the whole construction schedule. This article introduces the main causes of positioning deviation, standard fixture requirements and acceptable rectification methods for on-site construction.

2026-11-03

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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

Flange Bolt Selection: Why Plain Washers Cannot Replace Integral Flange Face

Fastener Surface Treatment Comparison: Zinc Plating / Dacromet / HDG / Mechanical Galvanizing

Anchor Bolt Embedding Deviation: Positioning Error Causes Steel Structure Alignment Failure

Get A Free Quate

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