Precision compression, extension and torsion springs for industrial applications.
SPRINGS
Drawbar Spring Manufacturer — Electric Fencing, Marine and Industrial Applications
Drawbar springs are used wherever a tension spring is needed with built-in overload protection — the spring absorbs load and stretches, but cannot be pulled past its solid stop.
At Super Springs, we manufacture drawbar springs for electric fencing systems, marine mooring, tarpaulin and pool cover tensioning, gate mechanisms, porch swings and a range of industrial and commercial applications.
We supply manufacturers, distributors and aftermarket buyers across 14 countries from our ISO 9001:2015 certified factory in Gurgaon, India.
What is a Drawbar Spring
A drawbar spring is a compression spring fitted with two U-shaped wire drawbar arms — one at each end. This construction converts a compression spring into an extension spring, with one important difference: it has a built-in hard stop.
When a load is applied, the spring stretches as the drawbar arms extend. When the compression spring reaches its solid height, the spring stops — it cannot be extended further. This overload protection prevents the spring from being overstretched and failing catastrophically.
In a standard extension spring, excessive load causes the hooks to fail or the coils to yield permanently. A drawbar spring eliminates this risk. If the spring goes solid, the drawbar arms carry the load directly — the structure remains intact.
This is why drawbar springs are preferred over standard extension springs in outdoor, high-cycle and safety-critical applications.
Applications
Electric fencing
Drawbar springs are widely used in electric fence installations to maintain consistent wire tension. Fence wire expands and contracts with temperature changes and deflects when animals or vegetation make contact. A drawbar spring in the tensioning assembly absorbs these variations and keeps the wire taut — preventing sagging, shorts to earth and loss of shock effectiveness. The overload stop feature ensures the spring does not fail if the fence wire is pulled sharply.
Marine mooring
Drawbar springs — also called boat springs in some markets — are used to moor boats and yachts at shore. The spring is installed in the mooring line between the cleat and the vessel. It absorbs the surge load as the boat moves with waves and wind, reducing stress on the cleat fittings and the hull attachment points. SS304 stainless steel is the standard grade for marine use — salt water exposure makes spring steel unsuitable without heavy coating.
Tarpaulin and load securing
Drawbar springs are used to secure tarpaulins over trucks, trailers and storage areas. They attach between the tarpaulin eyelet and the vehicle hook. The spring maintains constant tension on the tarpaulin as the load shifts during transit, while allowing enough movement to prevent the tarpaulin from tearing at the fixing points.
Pool cover tensioning
Drawbar springs are used to tension safety pool covers and solar pool covers. They connect the cover to the anchor points around the pool edge, keeping the cover flat and under consistent tension. The overload protection prevents the spring from failing if a person or heavy object lands on the cover.
Gate and fence tensioning
Drawbar springs are used in gate closing mechanisms and perimeter fence tensioning where consistent pull-back force is required. The fixed stop prevents overloading when gates are slammed or held open against the spring.
Porch swings and garden furniture
A classic application — drawbar springs support the hanging load of porch swings and garden swing seats. The spring absorbs the dynamic load of the occupant's movement. The overload stop ensures the spring does not fail under sudden impact loading.
Industrial and commercial applications
Drawbar springs are used in a range of industrial settings where tension with overload protection is required:
• CNC machine spindles — maintaining constant preload during operation
• Hydraulic and pneumatic device release mechanisms
• Conveyor tensioning systems
• Door and access panel return mechanisms
• Material handling equipment — load securing and retention
The Key Advantage Over Standard Extension Springs
The most common reason buyers switch from standard extension springs to drawbar springs is repeated hook failure.
In a standard extension spring, the hooks are the weakest point. Under high load or repeated cycling, hooks fatigue and break — releasing the load suddenly. In outdoor applications like electric fencing and marine mooring, this type of failure is both a safety risk and a maintenance burden.
A drawbar spring eliminates hook failure. The drawbar arms are rigid wire forms — not hooks. The load is distributed through the arm and into the coil body, not concentrated at a single bend. When the spring reaches solid height, the arms carry the full load without any additional stress on the coil.
Standard Size Range
We manufacture drawbar springs in 7 standard sizes. All sizes are available in SH/DH spring steel and SS304 stainless steel.
Size Free Length (mm) Outer Diameter (mm) Wire Diameter (mm) Available in
1 130 24 3.0 SH/DH, SS304
2 175 32 4.0 SH/DH, SS304
3 220 42 5.0 SH/DH, SS304
4 275 52 6.0 SH/DH, SS304
5 340 62 7.0 SH/DH, SS304
6 420 72 9.0 SH/DH, SS304
7 525 85 12.0 SH/DH, SS304
Custom sizes outside this range are available to drawing or sample.
Key Design Parameters
- Free length (L) — the length of the spring when no load is applied. This determines how the spring fits in the assembly.
- Outer diameter (OD) — must fit within the attachment hardware with appropriate clearance.
- Wire diameter (d) — determines load capacity and spring rate. Heavier loads or longer spans need larger wire diameter.
If you are replacing an existing drawbar spring, measure all three dimensions from the old spring. If the spring failed due to fatigue rather than overload, consider moving up one wire diameter size for longer service life.
Materials
SH/DH spring steel — for indoor and protected outdoor applications
SH/DH is a high carbon, double drawn spring steel. It has high tensile strength and good fatigue life. Supplied with zinc white plating for corrosion protection. Suitable for electric fencing, gate mechanisms, tarpaulin securing and indoor industrial use where some moisture exposure is expected.
SS304 stainless steel — for marine, coastal and aggressive outdoor use
SS304 stainless steel is the correct choice for any application with salt water exposure, continuous moisture or aggressive outdoor conditions. Marine mooring, coastal electric fencing, outdoor pool covers and any application in the Middle East, Southeast Asia or coastal markets. No coating required. Available across all 7 standard sizes.
Applications
We manufacture drawbar springs at our factory in Gurgaon, India. Our capability includes:
• Wire diameters from 3.0 mm to 12.0 mm
• Free lengths from 130 mm to 525 mm in standard range — custom lengths available
• SH/DH spring steel and SS304 stainless steel
• Zinc white plating and surface finishing on steel grades
• In-house load testing
• Bulk production and export packaging for international supply
• Low MOQ for new product development and prototype orders
40+ years of manufacturing. ISO 9001:2015 certified. Exporting to 14 countries including Germany, UK, Malaysia, South Africa, Chile and UAE.
Custom Drawbar Springs
We manufacture custom drawbar springs for applications not covered by the standard range.
• Manufacturing to drawing — provide free length, OD, wire diameter and grade
• Sample replication — send a physical sample for measurement and replication
• Modified standard sizes — adjusted length or diameter based on a standard size
• OEM supply — consistent bulk production for equipment and fencing manufacturers
• Private label packaging — for distributors supplying under their own brand
Over time, we’ve realised that most customers are not looking for a “vendor” — they’re looking for a dependable manufacturing partner.
What matters to them:
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Consistency across batches
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Predictable performance
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Clear communication
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Long-term reliability
That’s exactly what we focus on.
Frequently asked Questions
Why use a drawbar spring instead of a standard extension spring?
A drawbar spring has a built-in hard stop — when the compression spring reaches solid height, it cannot be extended further. This prevents catastrophic hook failure and overloading. In applications like electric fencing, marine mooring and tarpaulin securing, this overload protection significantly extends service life and reduces maintenance.
Which grade should I use for electric fencing?
For standard electric fencing in normal agricultural or commercial environments, SH/DH spring steel with zinc white plating is suitable. For coastal locations, marine environments or areas with high rainfall and humidity, SS304 stainless steel is recommended.
Which grade should I use for marine mooring?
SS304 stainless steel. Salt water and marine atmosphere will corrode spring steel regardless of plating. SS304 is the correct material for any mooring, dock or waterfront application.
Can I get the springs in SS304 across all sizes?
Yes. All 7 standard sizes are available in both SH/DH spring steel and SS304 stainless steel.
What is the minimum order quantity?
MOQ depends on size and specification. We accommodate low MOQ orders for new product development and aftermarket supply. Contact us with your specific requirement.
Can you supply custom sizes?
Yes. Provide free length, outer diameter, wire diameter and grade. Custom sizes are manufactured to drawing or sample. Prototype quantities are available before bulk production commitment.
Do you export drawbar springs?
Yes. We export to 14 countries. Packed in corrugated boxes suitable for sea freight. We handle export documentation, commercial invoices and certificates of origin for all our export markets.
