What is a Single-Turn Wave Spring?
A single-turn wave spring (also referred to as a single-layer wave spring or wave washer) features a single circular turn of continuous sinusoidal waves formed from flat wire. It is the most economical and space-efficient member of the wave spring family. Available in two common end configurations—Gap Type (with a circumference split allowing radial expansion without binding) and Overlap Type (with overlapping ends providing continuous 360° support in heavier applications).
Operating height is approximately 50% lower than that of an equivalent conventional helical compression spring providing identical load, making single-turn wave springs the premier choice for light-to-medium axial preloading in compact mechanical housings.
Typical Geometric & Operating Parameters
Standard manufacturing capabilities and dimensional scope for TOSTA single-turn wave springs:
| Parameter | Range | Engineering Notes |
|---|---|---|
| Wire Thickness (t) | 0.08 – 3.0 mm | Precision cold-rolled flat wire with radiused edges |
| Outer Diameter (OD) | 3 – 200 mm | Micro miniature to heavy industrial sizes |
| Free Height (H₀) | 0.5 – 15 mm | Working height typically engineered at 30%–50% of H₀ |
| Number of Waves (N) | 2 – 12 Waves | Higher wave counts distribute load evenly and lower stiffness |
| Load Capacity (P) | 1 – 500 N | Scalable based on radial width and strip thickness |
5 Primary Industrial Applications
- Bearing Preloading: Eliminates axial internal play and reduces operational vibration and noise in electric motors, gearboxes, and high-speed spindles.
- Mechanical Face Seal Compensation: Provides steady axial contact force against carbon and ceramic seal rings across thermal cycles, preventing fluid leakage.
- Electrical & Bayonet Connectors: Delivers reliable mating force and vibration resistance in aerospace multipin plug shells and quick-disconnect fittings.
- EV & Battery Pack Clamping: Buffers expansion and contraction of cylindrical lithium battery cells (18650, 21700) under thermal charging and discharging cycles.
- Precision Optical & Sensor Assemblies: Offers micro-deflection positioning and zero-play preloading for lenses, laser collimators, and micro-actuators.
Engineering Selection Guidelines
- Determine available axial working space: keep working height within 30%–50% of the spring free height for optimal linear load predictability.
- Calculate required working load with a safety factor of 1.2–1.5, then reverse-engineer wave count (N), radial wall thickness (b), and strip thickness (t).
- Choose alloy material: carbon spring steel for standard machinery; SUS304/SUS316 for chemical or marine service; SUS301 or 17-7PH for high fatigue strength.
- Verify dynamic fatigue safety: ensure cyclic stress amplitude does not exceed 50% of the material yield strength.
- Account for thermal and magnetic constraints: select nickel superalloys (Inconel 718) above 300°C, and beryllium copper for magnetic-free MRI applications.
Material Options & Performance Matrix
TOSTA maintains a continuous raw material stock of over 500 tons across 6 standard alloy systems for rapid single-turn wave spring manufacturing:
| Alloy Grade | Mechanical Properties (E / Tensile / Service Temp) | Primary Engineering Application |
|---|---|---|
| 65Mn Carbon Steel | 206 GPa / 980–1275 MPa / -40°C to +120°C | General machinery, cost-effective high-volume automotive parts |
| SUS301 Stainless Steel | 193 GPa / 520–1100 MPa / -200°C to +300°C | Precision bearing preload, electronic connector contacts |
| SUS304 Stainless Steel | 193 GPa / 515–1035 MPa / -200°C to +300°C | Food processing, medical equipment, mild atmospheric exposure |
| SUS316 / 316L Stainless | 193 GPa / 480–1300 MPa / Pitting resistance | Marine saltwater hardware, chemical pumps and fluid valves |
| 17-7PH (UNS S17700) | 204 GPa / 1150–1650 MPa / -100°C to +340°C | High-stress aerospace mechanisms, high-cycle dynamic fatigue |
| Inconel 718 (UNS N07718) | 200 GPa / 1240–1430 MPa / -250°C to +700°C | Gas turbines, nuclear valves, downhole oil exploration tools |
International Standards Compliance
All TOSTA single-turn wave springs are produced and inspected in strict accordance with international standards:
- DIN 17222 / DIN EN 10132-4 — Cold rolled steel strip for springs.
- DIN 2077 — Spring washers and curved spring elements.
- ISO 26909 — Springs vocabulary and technical documentation.
- ISO 2162 — Technical product documentation of springs.
- ASTM A313 / A313M — Standard specification for stainless steel spring wire.
- MIL-STD-1312 — Fastener test methods for aerospace spring components.
Frequently Asked Questions (FAQ)
Q1: How do single-turn wave springs differ from conventional stamped wave washers?
While structurally similar in appearance, stamped wave washers typically have only 2–3 coarse waves, limited travel, and wide load tolerances intended solely for anti-loosening. Single-turn wave springs feature 2–12 precisely calculated wave crests made from cold-rolled edge-conditioned flat wire with predictable linear load-deflection characteristics and tight load tolerances.
Q2: How do engineers select the optimal number of waves (N)?
For a given outer diameter and strip thickness, a higher wave count reduces the individual wave span, lowers stiffness, and distributes load contact points more uniformly around the circumference. Use more waves for compliant, uniform preloads, and fewer waves when higher axial stiffness is needed.
Q3: What is the recommended working height range?
Operating heights should be maintained within 30%–50% of the free height. In this range, the load-deflection curve is highly linear and repeatable. Compressing the spring past 70% toward solid height causes sharp exponential stress spikes, leading to early fatigue or permanent set.
Q4: What are the minimum order quantities and delivery lead times?
TOSTA maintains over 9,000 standard sizes in inventory with 1-piece MOQ dispatched within 24 hours. Custom dimensions are tooled and delivered in 1–3 business days with automated daily capacity exceeding 30,000 pieces.
Q5: What are the critical installation precautions?
Single-turn wave springs must be loaded purely along the axial direction. Seating surfaces should be flat and perpendicular to the axis of motion. Ensure sufficient radial clearance between the spring OD and bore wall (or ID and shaft) to accommodate outward radial expansion as the spring compresses.
Need Single-Turn Wave Spring Engineering or Prototyping?
TOSTA provides rapid customized single-turn wave springs in SUS301, SUS304, SUS316, 17-7PH, and Inconel 718 with sample delivery in 1–3 business days.