OpeningYour drawing defines the spring. We build it exactly to that print. Double coil torsion springs carry load in two parallel legs, which means tighter angular control and high
Custom Double Coil Torsion Springs | Precision Manufacturing China
OpeningYour drawing defines the spring. We build it exactly to that print. Double coil torsion springs carry load in two parallel legs, which means tighter angular control and higher torque in a compa
Get a Fast Quote for This Part
Send us your drawing / quantity / material — reply within 24h.
Your drawing defines the spring. We build it exactly to that print. Double coil torsion springs carry load in two parallel legs, which means tighter angular control and higher torque in a compact space. That geometry demands precision. We deliver it.
Every unit is verified before shipment. We check coil diameter, leg position, free angle, and load at deflection. If it does not match your tolerance, it does not leave the factory.
Tolerance: ±0.05 mm on wire diameter, ±1° on angular position
Lead time: 7–12 days for prototypes, 15–20 days for production
No MOQ: order 1 piece or 100,000 pieces
Material certs: EN 10270-1, ASTM A228, ASTM A313 available
Inspection report: included with every batch
Specifications
Parameter
Value
Notes
Wire diameter
0.1 mm – 12 mm
Round, square, or rectangular wire
Coil diameter (OD)
1.0 mm – 80 mm
Tolerance ±0.05 mm
Number of coils
2 – 20
Custom per drawing
Leg length
2 mm – 150 mm
Straight, bent, or hooked ends
Leg angle (free position)
0° – 360°
Tolerance ±1°
Torque range
0.01 N·m – 50 N·m
Verified on test fixture
Materials
Music wire, stainless steel 302/304/316, 17-7PH, Inconel, phosphor bronze
Other alloys on request
Surface finish
Zinc plating, nickel plating, electropolishing, black oxide, passivation
100% dimensional check on critical features, load testing per batch
CMM and optical comparator
Three reasons buyers send us their drawings
1. Batch-traceable quality
Each batch gets a unique job number. We record wire lot, heat treat cycle, and final inspection data. If a problem appears in your assembly line, we trace it back to the exact coil and operator. That is precision manufacturing you can audit.
2. Inspection report per batch
You do not have to guess if the springs meet spec. Every shipment includes a dimensional report, load test data, and material certificate. We measure free angle, coil gap, and torque at your specified deflection. If you need PPAP Level 3, we provide it.
3. One factory for CNC, stamping, springs, and heat sinks
Your torsion spring might need a stamped bracket, a CNC-machined shaft, or a heat sink for a high-temp application. We do all four in-house. One drawing package, one quality system, one shipping point. Fewer vendors, fewer delays, fewer excuses.
Where these parts are used
Double coil torsion springs handle higher loads than single coil versions without increasing wire diameter. That makes them the default choice in demanding mechanical systems.
Automotive: seat belt retractors, clutch pedals, throttle return mechanisms, door handles. Vibration and temperature cycling are normal here. Our springs survive both.
Aerospace: actuator linkages, control surface trim systems, latch mechanisms. Material certs and full traceability are mandatory. We meet AS9100 standards.
Medical devices: surgical staplers, retractors, insulin pen mechanisms. Springs must be corrosion-resistant and consistent over thousands of cycles. We use 316 stainless and electropolish for clean surfaces.
Industrial equipment: safety interlocks, valve returns, conveyor tensioners, circuit breakers. High cycle life and repeatable torque are critical. We shot peen and preset to prevent sag.
Consumer products: folding knives, eyeglass hinges, laptop hinges, toy mechanisms. Tight tolerances keep assembly lines running without adjustment.
Q: Is there really no MOQ?
A: Yes. We run prototypes from 1 piece. For production, we batch efficiently to keep your unit cost low, but we never turn down a small order. Many customers start with 50 pieces for field testing, then scale to 50,000.
Q: How do you guarantee tolerance and quality?
A: We use CNC coiling machines with closed-loop feedback. After coiling, we heat treat and stress relieve. Then we measure every critical dimension on an optical comparator or CMM. Load testing is done on a calibrated torque tester. The inspection report is included with your shipment.
Q: What is the lead time for custom springs?
A: Prototypes ship in 7–12 days after drawing approval. Production runs take 15–20 days, depending on quantity and surface finish. We offer expedited service for urgent projects—just ask.
Q: Can you provide material certificates?
A: Yes. We supply EN 10270-1, ASTM A228, and ASTM A313 certificates with every batch. For aerospace or medical, we add full traceability documentation and can perform third-party testing if your spec requires it.
Send your drawing
Stop waiting on generic catalog springs. Send us your drawing, and get a firm quote in 12 hours. We will review the geometry, suggest material options if needed, and confirm lead time. No MOQ, no hidden fees, no surprises.
Email: sc@bquq.com
WhatsApp: +86 13713157787
Precision manufacturing, made in China, with 20 years of spring experience behind every coil. Your drawing is the only thing we need to start.
