The hook must fit the finished assembly without rework
Hooks formed strictly to drawing: German, English, coiled loops, threaded ends
Custom Extension Springs — Hooks in Any Configuration
German and English hooks, coiled loops, threaded ends. We manufacture to drawing or sample — with force calculation and initial tension matched to your application.
- Wire diameter
- 0.1–80 mm
- Hook shape
- to drawing
- Quality system
- IATF 16949:2016
An engineer replies within one business day (Moscow + 5 hours). Prototypes — 48 hours after drawing approval.
1 979
founded
47 years in spring manufacturing
145
employees
many with 15+ years in the industry
900 t
springs per month
maximum capacity
60+
coiling machines
cold and hot coiling, CNC
Problems we solve
Your problem — our solution
The force is off — the mechanism does not work as designed
We select geometry and initial tension for the required force
Seasonal demand cannot wait for long lead times
Prototypes in 48 hours, then a fixed schedule for series deliveries
Technical parameters
Made for your conditions
| Wire diameter range | 0.1–80 mm |
|---|---|
| Materials | 65Mn, 72A, 82B, 60Si2Mn, 55CrSi, 51CrV4, 60Si2CrMn |
| Coatings | Zinc plating, nickel plating, cataphoresis, Dacromet, black oxide, preservative oil |
| Documents | IATF 16949:2016 certificate, test reports, product data sheet |
Process
How we make it
- 01 Cold coiling
- 02 loop forming
- 03 heat treatment
- 04 coating
Wire is sourced directly from Baowu (Baosteel), Kobe Steel, Bekaert and Qingdao Special Steel — that is what gives consistent characteristics from batch to batch.
Applications
Where this category works
- Tensioning devices and latches
- Agricultural machinery, balers
- Furniture hardware and fittings
- Brake and return mechanisms
Industries we already supply
Construction and Road Machinery Series batches of compression and extension springs for tensioning, return and damping assemblies of construction machinery. View industry Agricultural Machinery The full set: extension, compression and torsion springs plus wire forms made to drawings. View industry Garage and Roller Doors Torsion springs of the R series (residential) and C series (commercial doors) and extension springs for door mechanisms. View industry
Advantages
Why factories choose XULONG SPRING
Proof, not promises
Quality control of every batch
What removes the risks of sourcing from China
- NDA on request Drawings and technical documentation are never shared with third parties or used for other customers.
- Prototypes in 48 hours You test the samples first — series production is agreed only after your approval.
- Reports for every batch Load, geometry, hardness — with measurement protocols and batch traceability.
- Document package for EAC IATF 16949:2016 certificate, test reports and product data sheets — for declaration and customs.
- Payment in CNY Payment terms and channel are agreed individually before the order is signed.
- Delivery to Russia Rail, road and sea freight via the Far East. Incoterms: FOB, CIF, DAP.
How to start — three steps
- 01
Send a drawing or a sample
PDF, DWG, DXF, a sketch or a physical sample. We sign an NDA on request.
- 02
Get a price and lead time
Our engineer checks manufacturability and proposes material and coating — we reply within one business day.
- 03
Test prototypes in 48 hours
After alignment we produce prototypes and ship them to you. Then — a series batch with inspection and documentation.
FAQ
Questions about extension springs
Can we order these extension springs made to our drawing?
Yes. We accept drawings in PDF, DWG and DXF, sketches and physical samples. Standard prototyping lead time is 48 hours after the drawing and material are approved.
Which material and coating do you recommend?
The selection depends on the operating conditions: temperature, load and environment. Our engineer will propose a steel grade (65Mn, 60Si2Mn, 55CrSi, 51CrV4, etc.) and a coating — from zinc plating to Dacromet.
How are the price and minimum order calculated?
The price depends on wire diameter, material, coating and batch volume. Send a drawing with the required quantity — we will reply with a price, lead time and minimum volume.
How do you deliver products to Russia?
We arrange rail container transport, road freight and sea shipping via Far East ports. Delivery terms (FOB, CIF, DAP) are agreed per order.
Can we sign a confidentiality agreement?
Yes, we work under NDA: customer drawings and technical documentation are never shared with third parties or used for other customers.