Your Professional Extension Springs Supplier
Zhuji Xuanyu Spring Co., Ltd. (formerly Zhuji Printing Machine Spring Factory) is a high-quality spring manufacturer with 28 years of professional experience, recognized as a pioneer and leader in China’s printing press and die-cutting machine industries. We are consistently dedicated to providing exceptional spring solutions for our clients.
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Swivel Hook Extension SpringUnlike standard fixed-hook extension springs, this design allows multi-angle movement, misalignment compensation, and dynamic load adaptation during operation. It effectively reduces stress
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Double Hook Extension SpringsXuanyu Springs supports custom-made non-standard parts for various double-hook tension springs. We can provide full technical support and flexible production solutions, from material selection and
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Garage Door Extension SpringsXuanyu Springs is a professional manufacturer and solution provider of garage door springs for the global market. We focus on providing one-stop, high-performance, and customizable garage door
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Stainless Steel Extension SpringsStainless steel tension springs are elastic elements made of high-quality stainless steel wire that store and release energy through stretching and deformation. Their key feature is their superior
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Carbon Steel Extension SpringsCarbon steel extension springs are critical components that store and release energy through elastic deformation. They maintain a compact helical state when unloaded and extend quickly when subjected
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Zinc-plated Extension SpringsA galvanized tension spring is an elastic component that stores and releases energy through stretching and deformation.In its natural state, a spring remains tightly coiled; when subjected to
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Trampoline Extension SpringsThe trampoline tension spring is the core elastic component connecting the jumping mat and the rigid frame. Its performance directly determines the trampoline's bounce height, cushioning, safety, and
Why choose us
Quality Control
We maintain a strict internal inspection process. Each batch of products undergoes multiple tests, including accuracy, pressure resistance, and service life. Key inspection data can be provided upon request.
Logistics Solutions
With extensive export experience, we can arrange sea freight or international express delivery (DHL, FedEx, etc.) and offer trade terms such as FOB Ningbo/Shanghai to ensure safe and efficient delivery.
Sales Market
We have established stable supply partnerships in Southeast Asia, Europe, North America, and the Middle East, and we have served customers from countries such as Germany, Japan, the United States, and India for many years.
Our Service
From order placement to shipment, we maintain close communication. You can track order progress at any time, and we can provide photos or videos of key production stages upon request, allowing you to monitor quality remotely.
Product Description
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Model |
Extension springs |
|
Material Type |
SS302(AISI302)/ SS304(AISI304)/ SS316(AISI316)/SS301(AISI301)/SS631/65Mn(AISI1066)/60Si2Mn(HD2600)/55CrSiA(HD1550)/Music wire/C17200/C64200, Etc. |
|
Wire diameter |
0.1~20 mm |
|
I.D |
>=0.4 mm |
|
O.D |
>=0.6 mm |
|
Free length |
>=3 mm |
|
Body Length |
>=0.5 mm |
|
Total Coils |
>=2 |
|
Hook Type |
Cross over hook, extended hooks, machine hooks, side hooks |
|
Hook Length |
>=1 |
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Tolerance |
>=0.05 mm |
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Packaging |
PE bags, Cartons, Pallets |
|
Warranty period |
One year |
|
Application |
Electronic producats, Children toys, Baby carriage, Bicycle, Kitchen appliances, Cameras, Printers, Office equipment, Precision equipment and various kinds of vehicles |
|
Finish |
Zinc plating, Nickel plating, Anodic oxidation,Black oxided,Electrophoresis, Power coating, Gold plating, Silver plating, Tin plating, Paint,Chorme, Phosphate, Dacromet,Oil coating, Copper plating, Sand blasting, Passivation, Polishing,Etc. |
|
Notes |
1. Please offer us your spring spec,we can make spring based on your requirements. |
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2. Discount offered if with large order quantity. |

Our custom spring manufacturing capabilities include:
• The common wire diameter for extension springs ranges from 0.1mm to 25.00mm, and non-standard customization is supported.
• A variety of ends, including twist, German hooks, cross center, side loops, flat stock hooks and extended hooks.
• An array of material types including stainless steel, music wire, hard drawn and more.
• Custom extension spring designs to match your specific requirements and tensions.
We have the expertise and latest equipment to design and manufacture your next extension spring order.
How to Measure an Extension Spring
Proper measurement is crucial to ensure that an extension spring fits and functions as intended in its application. Here’s how to measure the key dimensions of an extension spring:
Wire Diameter (WD): The thickness of the spring wire is one of the most important measurements. To measure the wire diameter, use a digital caliper and place it around the wire to get an accurate reading. Small variations in wire diameter can significantly impact the spring’s performance.
Outer Diameter (OD): This is the distance across the outermost part of the spring coil. To measure it, use a caliper to measure from one side of the coil to the opposite side at its widest point. This ensures that the spring will fit properly in the housing or space it is intended for.
Free Length (FL): The free length is the total length of the spring, including the coils and any hooks or loops. To measure this, stretch the spring gently so that it is not under load, and use a ruler or caliper to measure from one end of the spring to the other.
Total Coils (TC): Count the number of full coils in the spring, excluding any that form the hooks or loops. The number of coils affects the spring’s tension and overall flexibility, so this is an important factor to consider.
Hook Type: Measure the length and shape of the spring’s hooks or loops to ensure they will fit within your assembly. Different hook types provide different levels of strength and durability, so this is crucial for selecting the right spring.
We offer a wide range of materials to suit various applications
Stainless Steel
Corrosion-resistant and durable.
01
Steel
Provides high tensile strength.
02
Wire
Versatile options for diverse needs.
03
Copper
Excellent conductivity.
04
Brass
Resistant to corrosion and wear.
05
Before manufacturing extension springs, designers and manufacturers need to work together to determine the important parameters of each spring. In extension springs, designers need to define:
Spring diameter: The size of a circular spring’s cross section.
Free length: The length of the spring when at rest.
Maximum extended length
The farthest the spring can be stretched without damaging or overstressing the spring.
Ends
The loops or hooks at each end of the spring.
Wire diameter
Along with material, wire diameter does a lot to determine the behavior of the spring.

Certificates


FAQ
As one of the most professional extension sprins manufacturers and suppliers in China, we're featured by quality products and good service. Please rest assured to wholesale bulk customized extension sprins made in China here from our factory. Contact us for more details.
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