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

Washer Matching Misunderstanding: Not Every Assembly Needs a Plain + Spring Washer Combination

2026-10-14

Targeting the habitual pitfall of overseas procurement teams that every bolt joint must be equipped with both a plain washer and a spring washer, this article analyzes the structural differences between the two washers, clarifies the stress concentration and preload inaccuracy caused by over-stacking, and outputs standardized matching rules. It helps overseas engineering teams avoid wrong complete-set matching and improve connection reliability.

2026-10-14

Fastener Selection for Outdoor Acid Rain Environment: Normal Zinc Plating White Chalking Failure

2026-10-13

Aiming at the common foreign trade failure issue that ordinary electro-galvanized fasteners rapidly generate white powder and coating delamination in overseas rainy acid regions, this article explains the acid rain corrosion principle of zinc coating, compares multiple anti-corrosion coating performance and applicable boundaries, sorts out typical procurement misunderstandings, and outputs coating selection guidelines for acidic outdoor projects. It helps overseas engineering teams avoid premature corrosion failure, reduce after-sales disputes and project rework risk.

2026-10-13

ISO 4014 Hex Head Bolt Partial Thread.png

Stainless Steel Bolt Cold Welding: Non-heat On-site Removal Tips

2026-10-12

Targeting the high-frequency overseas maintenance failure of stainless steel bolts being seized and locked during assembly, this article explains the cold welding principle of 304/316 threads and why high-temperature working conditions aggravate galling, lists the risks of violent forced disassembly, and provides vibration loosening, penetrating soaking and low-temperature cooling removal methods. It also gives assembly standards to prevent thread self-locking, helping overseas engineering and maintenance teams remove seized bolts safely and reduce scrapped fasteners.

2026-10-12

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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

Washer Matching Misunderstanding: Not Every Assembly Needs a Plain + Spring Washer Combination

Fastener Selection for Outdoor Acid Rain Environment: Normal Zinc Plating White Chalking Failure

Stainless Steel Bolt Cold Welding: Non-heat On-site Removal Tips

Get A Free Quate

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