Tension Springs Supplier

Extension Springs Manufacturer & Custom Extension Spring

We are an excellent extension springs manufacturer and supplier. KENENG specializes in the design and manufacture of stock and custom extension springs in a wide variety of sizes and specifications. We have excellent manufacturing capabilities and can provide a variety of materials, sizes, end types, lengths, spacing configurations, surface treatments, and optional certifications. In addition to custom tension springs to your drawings and requirements, we also stock a number of standard tension springs.

As a China tension springs manufacturer, we have senior technicians with many years of spring production experience to design and customize springs for you, and we also have a variety of testing equipment to assist spring production. While we try our best to help you reduce the cost of using spring parts, we also focus on improving product quality, stability, and assembly efficiency.

Are You an OEM Manufacturer?


Extension Springs Display

Custom Extension Springs

KENENG is a custom extension spring manufacturer. We produce both standard extension springs as well as custom sizes and styles.

Non-standard spring customization needs customers to coordinate design and production with us, according to the actual use of the environment, installation space, pressure size to choose the material of the spring, line diameter, size, and special surface finishing.

Please inform us of the following basic data when ordering, so as to customize.

1. Specifications: Wire diameter, OD(Outside diameter) or ID(Inside diameter), Free length, Coil numbers, Active coil numbers.

2. Technical requirements:

  • Turing direction (left hand/right hand)
  • Material(music wire, spring steel, carbon steel, stainless steel, copper/brass, Ti/Ti alloy, super alloy, etc)
  • Surface finishing(black oxide, galvanized, nickel plated, gold plated, silver plated, phosphating, color coding, shot peening, sandblast, etc)
  • Spring force
  • End type (Closed, Grounded, Close and grounded, Open)
  • Hook form (round hook/half round hook/U hook/middle ear/side hook)

If you have any needs, please contact KENENG, we will provide you with the best quality service.

Custom Tension Springs Case

Tension springs are widely used in many fields around the world, including molds, construction machinery, ships, electronics, automobiles, medicine, aerospace, railways, wind power, thermal power, mining machinery, national defense, etc.

We always adhere to the principle of “quality first”, select qualified materials, adopt advanced equipment, use professional production technology, adhere to a serious, responsible, United, and innovative working attitude, produce high-quality products, and provide humanized services, which has won the recognition of customers at home and abroad. As a popular extension spring manufacturer, we welcome customers at home and abroad to negotiate business. We will welcome you with high enthusiasm!

Types of Custom Extension Springs

KENENG is a tension springs supplier, we can customize tension springs. The following common tension spring parameters are provided below, which you can choose. If the type you want to choose is not included in the list, please contact us, and customer service will customize the service for you.


  • Music wire
  • Spring steel
  • Carbon steel (65Mn, 60Si2MnA, 55SiCr, 50CrVA, etc.)
  • Stainless steel (201, 304, 316, 316L, etc.)
  • Copper/Brass
  • Ti/Ti alloy
  • Monel
  • Hastelloy
  • Inconel


  • Wire diameter 0.1~80mm
  • OD and length as per customer’s requirements.


  • Black oxide
  • Plating (Zinc, Nickel, Tin, Gold, Silver )
  • phosphating
  • powder painting & color coding
  • shot peening
  • sandblast


  • production assembly
  • experimentation
  • research and development
  • national defense
  • marine
  • computer
  • electronics
  • automobile
  • mold
  • medicine
  • biochemistry
  • aerospace
  • railway
  • nuclear power
  • wind power
  • thermal power
  • construction machinery
  • mining machinery
  • elevators, etc.

Materials We Can Custom Tension Springs

KENENG can custom extension springs in carbon steel, stainless steel, copper, brass, Monel, Hastelloy, Inconel, Titantium, Ti alloy, and more.

What is Tension Springs?

The tension spring is one of the helical springs, which is a spring that bears axial tension. The characteristic of the extension spring is that when it is not under load, the coils of the extension spring are generally tight and there is no gap.

What is the Difference Between a Compression Spring and a Tension Spring?

The most obvious difference is that there is usually a certain gap between the rings of the compression spring, and the spring will shrink and deform when subjected to an external load.

What is the Difference Between a Tension Spring and a Torsion Spring?

The significant difference between extension springs and torsion springs is the difference in force:

  • When the spring is subjected to a pulling force along the axial direction, it is a tension spring, and under the action of the axial force, it generates a reverse elastic force along the axial direction.
  • When a spring is subjected to a torque around an axis, it is a torsion spring.

In order to facilitate the application of tension or torsion, the two ends of the spring are often made into a more suitable shape according to the usage.

The Order Process of Custom Extension Springs

OEM: Receive pictures or samples

  • Design & drawing process
  • Make sample, approval by customer
  • Confirmation on order detail
  • Signing Pi
  • Receive deposit
  • Mass production
  • Receive Balance
  • Delivery

ODM Customer has no design:

  • Design & drawing process
  • Quotation
  • Payment of design fee
  • Make CAD or 3D design
  • Make sample, approval by customer
  • Confirmation on order detail
  • Signing Pi
  • Receive deposit
  • Mass production
  • Receive Balance
  • Delivery

ODM Customer has design:

  • Receive design
  • Quotation
  • Payment of design fee
  • Make CAD or 3D design
  • Make sample, approval by customer
  • Confirmation on order detail
  • Signing Pi
  • Receive deposit
  • Mass production
  • Receive Balance
  • Delivery

Lathe parts(non-standard parts)

  • Receive CAD or 3D design
  • Quotation
  • Signing Pi
  • Receive deposit
  • Make sample, approval by customer
  • Mass production
  • Receive Balance
  • Delivery

Stamp part

  • Receive CAD or 3D design
  • Quotation
  • Signing Pi
  • Receive deposit
  • Make prototype
  • Open molding
  • Trial production
  • Mass production
  • Receive Balance
  • Delivery

Injection Molding

  • Receive CAD or 3D design
  • Quotation
  • Signing Pi
  • Receive deposit
  • Make 3D or Prototype sample
  • Analyse Molding
  • Design
  • Open Molding
  • Make sample, approval by customer
  • Mass production
  • Receive Balance
  • Delivery

Extension Spring Manufacturer

We are a professional tension springs manufacturer. KENENG has been focusing on the design, development, manufacturing and surface treatment of extension springs for 17 years.

Advantages of KENENG:

1. It can process and produce various 0.1-90mm compression springs, tension springs, torsion springs, disc springs, leaf springs, special-shaped springs, etc.

2. Our company has complete production and testing equipment and advanced production technology. It has various specifications of fully automatic computer spring coiling machine, computer spring grinding machine, continuous mesh belt quenching furnace, tempering furnace, spring tension and compression testing machine, spring fatigue testing machine,  cold coil spring machine, hot coil spring machine, etc.

Production equipment for Extension Springs

What Processes Can We Use to Produce Extension Springs?

Production Equipment for Extension Springs

Application of Extension Springs

KENENG can produce tension springs used in many industries, including ocean, electronics, automobile, mold, medicine, aerospace, railway, energy, machinery, and other fields.

For Example:

Related Springs Products

News of Extension Springs

FAQ of Extension Springs

a. The design and manufacturing parameters of non-standard spring are unreasonable: only pay attention to the outer diameter, inner diameter, length and other parameters, and often ignore the size of wire cross-sectional area and pitch, resulting in smaller force;

b. Unreasonable model selection of standard spring: due to the low price, the light load type is selected and cannot bear the heavy load;

c. Wrong spring quality grade: inadvertently or deliberately use ordinary springs as high-quality springs or imported springs;

d. The elasticity is reduced or even lost due to the use at a temperature exceeding the specified temperature;

e. The spring wire itself is too soft, or the quenching temperature of the spring is too low or the holding time is not long enough, or the tempering temperature of the spring after forming is too high and the time is too long, resulting in insufficient tensile and compressive strength.