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

Grade12.9SocketCapDIN912Self-Colour.webp

Inner Hex vs Outer Hex Bolt: Installation Space & Working Boundary

2026-09-24

Aiming at the foreign trade engineering pain point of on-site rework and construction failure caused by blind replacement of inner hex and outer hex bolts, this article compares the two fasteners in terms of structural space requirements, tool matching, locking performance and maintenance adaptability, clarifies the exclusive working condition boundaries of compact hidden space and open load-bearing scenarios, summarizes common selection pitfalls, and provides accurate and cost-effective bolt matching guidelines for overseas mechanical equipment assembly projects.

2026-09-24

Normal Plating vs High Temperature Coating Fastener: Working Limit

2026-09-23

Aiming at the core foreign trade procurement pitfall that ordinary galvanized bolts are mistakenly used in high-temperature equipment leading to coating peeling and fastening failure, this article compares the process characteristics, temperature resistance limits and high-temperature stability of normal-temperature galvanizing and high-temperature anti-corrosion coatings, analyzes the failure mechanism of zinc layer peeling at high temperature, clarifies the exclusive working condition boundaries of the two processes, and provides professional and safe selection guidelines for overseas high-temperature furnace bodies, thermal pipelines and thermal energy equipment projects.

2026-09-23

GB vs DIN Fastener: Size Tolerance & Replacement Standard

2026-09-22

Aiming at the common foreign trade engineering problems of hole misalignment, tool mismatch and assembly failure caused by random replacement of GB and DIN fasteners, this article compares the two standards in terms of bolt head size, thickness tolerance, thread fit, washer parameters and countersunk sinking difference, summarizes safe replacement rules and forbidden boundaries, and solves the core pain points of standard mismatch in overseas project procurement and on-site maintenance.

2026-09-22

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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

Inner Hex vs Outer Hex Bolt: Installation Space & Working Boundary

Normal Plating vs High Temperature Coating Fastener: Working Limit

GB vs DIN Fastener: Size Tolerance & Replacement Standard

Get A Free Quate

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