Compression springs
Open or closed and ground ends, coiled to the free length and load on your drawing.
For contact pressure and mechanism return
Custom springs and wireforms, made to your drawing.
Compression, torsion and extension springs, wire clips and formed wire parts for breaker, contactor and switchgear mechanisms, and for any equipment built to a drawing. Manufactured in India, load tested against your drawing, and delivered to your Incoterm.
- Spring steel, stainless or bronze
- Load at deflection measured
- Measured records
Torsion spring, breaker handle returnDWG REV. B
- Material
- EN 10270-1 SH music wire
- Finish
- Zinc, trivalent passivation
- Critical value
- Torque 12 N·mm ±10% at 90°
- Inspection
- Torque and free angle measured
What we make
Torsion springs
Legs formed to the angle and direction on your drawing, wound left or right hand.
For breaker handles, latches and trip levers
Extension and closing springs
Hooked or looped ends, from light return springs to heavy springs that store closing energy.
For spring-charged ACB and VCB mechanisms
Wire clips and retainers
Clips, hinge pins and retainers that hold covers, guards and cables without tools.
For covers, doors and cable retention
Earthing springs and jumpers
Spring earthing contacts for doors and frames, and small solid-wire jumpers, tin or nickel plated.
For enclosures and wiring devices
Formed wire assemblies
Springs and wireforms joined with brackets, sleeves or terminals, supplied as one part.
For fewer incoming parts on your line
Springs in electrical equipment
In a breaker or contactor, the spring sets the contact force and the operating speed. Get the load wrong and the device runs hot, fails to trip or fails to close.
- MCBs and MCCBs
- Torsion springs return the handle and reset the trip latch. Compression springs hold the moving contact shut.If it is wrong: Low contact force raises contact resistance and heat; a weak trip spring changes when the breaker trips.
- ACBs and VCBs
- Closing and opening springs store the energy that closes and opens the breaker in a fraction of a second, charged by motor or by hand.If it is wrong: A spring that settles or cracks can leave the breaker unable to close fully, or to open on a fault.
- Contactors and relays
- Return springs open the contacts when the coil drops out. Contact springs set the force across the contacts.If it is wrong: Too weak and the contacts bounce or weld; too strong and the coil cannot pull in.
- Switch-disconnectors and earthing switches
- Snap-action springs drive the contacts open and closed at a set speed, whatever the operator does.If it is wrong: Slow operation draws an arc and burns the contacts.
- Draw-out and plug-in contacts
- Springs behind contact fingers and clusters set the pressure on plug-in joints.If it is wrong: Weak springs leave a hot joint at the plug-in contact.
- Enclosures and panels
- Earthing springs bond doors to frames; springs work the locks, hinges and interlocks.If it is wrong: A tired earthing spring breaks earth continuity on the door.
Choosing a spring
The movement decides the spring type. The duty decides the wire and the treatment.
Spring type for the movement
- Compression
- Pushes back when compressed. The most common mechanism spring, for contact pressure and return.Watch for: Long, slender springs buckle; give a guide rod or bore.
- Torsion
- Returns a lever or handle through an angle.Watch for: Give the leg angles free and loaded, and the winding direction.
- Extension
- Pulls back when stretched, through hooks or loops at each end.Watch for: The hook is the weak point; give its form and ask for stress relief.
Wire for the duty
- Music wire EN 10270-1
- The highest strength for its size, for most mechanism springs.Watch for: Rusts unless plated or oiled.
- Oil-tempered and chrome silicon EN 10270-2
- For heavy closing springs that work at high stress.Watch for: Usually shot peened and preset for long life.
- Stainless steel 1.4310, EN 10270-3
- Corrosion resistant, for damp and outdoor equipment.Watch for: Lower strength, so the spring comes out slightly larger.
- Phosphor bronze
- Conducts current and is non-magnetic, for springs in the current path.Watch for: Lower strength; more coils for the same load.
Treatment for a long life
- Stress relieving
- Heat treatment after coiling, so the spring keeps its shape and load.Watch for: Must come after coiling and before plating.
- Presetting
- The spring is compressed past its working length once, so it does not lose length in service.Watch for: Specify it for closing springs and high loads.
- Plating and baking
- Zinc or nickel plating against corrosion, then baking.Watch for: High-strength steel must be baked after plating to prevent hydrogen embrittlement.
Specifications
- Types
- Compression, torsion, extension and closing springs; wire clips and retainers; earthing springs and jumpers; formed wire assemblies
- Materials
- Music wire EN 10270-1; oil-tempered EN 10270-2; chrome silicon; stainless 1.4310 (EN 10270-3); phosphor bronze; copper and brass for jumpers
- Wire diameter
- 0.2–12 mm standard
- Dimensions
- Outside diameter, free length and leg angles to your drawing
- Tolerances
- EN 15800 for compression springs, or your drawing
- Processes
- CNC coiling and forming, stress relieving, presetting, shot peening, end grinding
- Finishes
- Zinc with trivalent passivation, nickel, tin; oiled; passivated stainless
- Checks
- Load at test length or torque at test angle; free length; wire and coil diameter; active coils; squareness; fatigue test where specified
- Quantities
- Prototype builds to mass production
Which spring wire
Strength, corrosion and current pull in different directions. The duty decides the wire.
Relative ratings for guidance, from published spring wire data. Your drawing and the load test decide.
Music wire, EN 10270-1
The highest strength for its size. Plated or oiled against rust.
Strength
3 / 3
Corrosion resistance
1 / 3
Conductivity
1 / 3
Chrome silicon steel
Holds load at higher stress and temperature, for heavy closing springs.
Strength
3 / 3
Corrosion resistance
1 / 3
Conductivity
1 / 3
Stainless steel, 1.4310
Resists corrosion in damp and outdoor equipment.
Strength
2 / 3
Corrosion resistance
3 / 3
Conductivity
1 / 3
Phosphor bronze
Carries current and is non-magnetic, for springs in the current path.
Strength
1 / 3
Corrosion resistance
2 / 3
Conductivity
2 / 3
| Wire | Strength | Corrosion resistance | Conductivity |
|---|---|---|---|
| Music wire, EN 10270-1The highest strength for its size. Plated or oiled against rust. | 3 / 3 | 1 / 3 | 1 / 3 |
| Chrome silicon steelHolds load at higher stress and temperature, for heavy closing springs. | 3 / 3 | 1 / 3 | 1 / 3 |
| Stainless steel, 1.4310Resists corrosion in damp and outdoor equipment. | 2 / 3 | 3 / 3 | 1 / 3 |
| Phosphor bronzeCarries current and is non-magnetic, for springs in the current path. | 1 / 3 | 2 / 3 | 2 / 3 |
Questions buyers ask
What do you measure on a spring?+
Load at a stated test length for compression and extension springs, or torque at a stated angle for torsion springs. We also measure free length, wire and coil diameter and active coils, and record them every batch.
Why do springs lose load, and how is that prevented?+
A spring that is not stress relieved or preset can settle, losing length and load in its first cycles. Stress relieving after coiling, and presetting for heavily loaded springs, keep the load where the drawing puts it.
What is hydrogen embrittlement?+
Plating high-strength spring steel can let hydrogen into the steel, which can make the spring crack later without warning. Baking soon after plating drives the hydrogen out.
Which tolerance standard do you work to?+
The one your drawing names. For compression springs that is often EN 15800, which sets grades for load, length and diameter.
Can you make a spring from a sample?+
Yes. We measure the wire, coils, free length and load, confirm them with you, and make samples for your approval. A drawing with the load at a stated length is best.
Do you make springs for equipment that is not electrical?+
Yes. We lead with electrical equipment because that is where most of our buyers work, but we make springs and wireforms to drawing for machinery, appliances and other equipment too.
Can you match an existing spring from another supplier?+
Yes. Send the drawing, and a sample if the drawing is incomplete. We tell you what can be held before we quote, then make samples for your approval.
Can you take a small order?+
Yes. Small, engineering-heavy batches are work we take, from prototype quantities upwards.
Send the drawing
Email us your enquiry at contact@qumek.com. We respond within 12 hrs.
Your enquiries are confidential with us and we proceed with manufacturing only after signing a NDA.
Need a DFM review, a prototype or a test plan before production? See the services.