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

news_main_image_9365975205_2240030356509024171259378421.jpg

Nyloc Nylon Insert Lock Nut: Anti-loosening Failure from Melting Under High Temperature

2026-10-22

Nyloc lock nuts (DIN985) rely on the nylon insert to create prevailing torque for anti-loosening performance. They work well at room temperature and will not scratch bolt threads, so they are widely selected for general industrial assemblies. The continuous temperature limit for standard PA66 nylon inserts is 120°C. Many buyers and mechanical engineers are unaware of this temperature limit and apply Nyloc nuts on high-temperature equipment such as heat exchangers, drying machines and exhaust assemblies. Under sustained heat, the nylon insert softens and melts, losing clamping force. The threaded joint will loosen gradually, leading to shutdown, safety hazards and order claims. This article explains the locking principle and thermal failure process of standard Nyloc nuts, compares alternative all-metal lock nuts, and lists key checking points for drawing and purchasing.

2026-10-22

Bolt Mill Test Certificate Review Checklist

2026-10-21

Mill Test Certificate (MTC) is a critical document for fastener export projects. Many export orders are detained or rejected overseas simply due to inconsistent heat numbers, mismatched material grades and non-compliant certificate formats. This article sorts out the standard audit checklist of bolt MTC, distinguishes MTC from COA, lists frequent non-conformity risks and provides a complete pre-shipment inspection process, helping fastener suppliers avoid huge losses caused by certificate issues.

2026-10-21

Fastener Anti-Rust Packaging | Prevent Container Rain Rust During Ocean Shipping

2026-10-19

This article addresses the frequent rust issue of fasteners caused by container rain during ocean transportation for foreign trade. It analyzes the corrosion mechanism of container condensation, compares multiple marine anti-rust packaging solutions, sorts out common misunderstandings of export packaging, and provides standardized packing procedures. It helps purchasing and engineering teams avoid the risk of cargo rejection due to rust upon arrival, and reduce claim and rework losses on overseas orders.

2026-10-19

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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

Nyloc Nylon Insert Lock Nut: Anti-loosening Failure from Melting Under High Temperature

Bolt Mill Test Certificate Review Checklist

Fastener Anti-Rust Packaging | Prevent Container Rain Rust During Ocean Shipping

Get A Free Quate

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