High-Quality Galvanized & Blackened Double-Headed Bolts 4.8/8.8 Grade - China Suppliers & Factory Suppliers, Manufacturers

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High-Quality Galvanized & Blackened Double-Headed Bolts 4.8/8.8 Grade - China Suppliers & Factory Suppliers, Manufacturers

Our double-headed bolts are expertly designed to address thread wear and damage that can occur with frequent disassembly, ensuring that the reliability and stability of the connection are maintained. As a leading supplier in China, we understand the importance of strong connections, which is why we implement anti-loosening measures to prevent threaded connections from loosening under external loads. Trust our factory for high-quality double-headed bolts that provide exceptional performance and durability in any application.

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Product Description

📋 Technical Specifications

Thread size d		M6	M8	M10	M12	M14	M16	M18	M20	M22	M24	M27	M30	M33
Designation		D	D	D	D	D	D	D	D	D	D	D	D	D
Designation		/	/	D-HDZ	D-HDZ	D-HDZ	D-HDZ	D-HDZ	D-HDZ	D-HDZ	D-HDZ	D-HDZ	D-HDZ	D-HDZ
ds	Max	5.32	7.16	8.99	10.83	12.66	14.66	16.33	18.33	20.33	22	25	27.67	30.67
ds	Min	5.14	6.97	8.78	10.59	12.41	14.41	16.07	18.07	20.07	21.69	24.69	27.34	30.34
S	Public	50	63	75	100	115	125	140	150	165	175	200	200	225
	Max	75	88	100	125	140	150	165	175	190	200	225	225	250
	Min	42	55	67	92	107	117	132	142	157	167	192	192	217
Connecting nut		M6	M8	M10	M12	M14	M16	M18	M20	M22	M24	M27	M30	M33

⚙️ The Function of Double Headed Bolts

🔗1. Connecting Mechanical Components

Double headed bolts have threads at both ends and a screw in the middle, commonly used to connect mechanical components such as mining machinery, bridges, automobiles, motorcycles, boiler steel structures, suspension towers, and large buildings.

🛠️2. Installation Accessories

When equipment requires accessories like observation mirrors or reduction frames, one end is screwed into the main body, and the other end is secured with a nut. This is ideal for parts requiring frequent disassembly.

🏗️3. Thick Plates & Inconvenient Areas

Perfect for thick connectors or areas where hexagonal bolts aren't practical, such as concrete roof trusses, roof beam suspensions, and monorail beam suspensions.

📍4. Fixed Connecting Rod

Commonly used for mechanical fixed connecting rods with corresponding threads at both ends. The middle screw thickness varies based on usage requirements.

❓ Frequently Asked Questions

QWhat is a double headed bolt and how does it differ from a standard bolt?

A double headed bolt (stud bolt) has threads on both ends with a plain or threaded shank in the middle. Unlike standard bolts with a head, these are screwed into a tapped hole on one side and secured with a nut on the other, ideal for frequent disassembly.

QWhat thread sizes are available for double headed bolts?

We offer a wide range of metric thread sizes, including M6, M8, M10, M12, M14, M16, M18, M20, M22, M24, M27, M30, and M33 to fit various structural applications.

QWhat is the difference between the "D" and "D-HDZ" designations?

"D" refers to standard double headed bolts, while "D-HDZ" refers to hot-dip galvanized versions. HDZ coating provides superior corrosion resistance for outdoor or marine environments (available from M10 and above).

QIn which industries are double headed bolts most commonly used?

They are widely used in construction (bridges, steel structures), heavy machinery (mining, boilers), transportation (automobiles, motorcycles), and infrastructure (suspension towers).

QWhy use double headed bolts instead of hexagonal bolts?

They are chosen when materials are very thick or space is limited for maneuvering a standard bolt. They allow secure fastening without needing access to both sides and prevent damage to base materials during maintenance.

QHow do I select the correct double headed bolt size?

Selection is based on thread size (d), shank diameter (ds), and required grip length (S). Refer to our specification table to match dimensions and choose the appropriate surface treatment (Standard or HDZ).

Product Detail

High-Quality Galvanized & Blackened Double-Headed Bolts 4.8/8.8 Grade - China Suppliers & Factory Suppliers, Manufacturers