Torque Limiting Screws for Safety and Precision in Assembly Lines
In modern assembly lines and precision equipment, applying the correct torque is critical. Too little torque can result in loose fasteners, while too much torque can cause plastic cracking, thread stripping, or sensor misalignment.
To solve this, engineers rely on Torque Limiting Screws—specialized fasteners designed to automatically disengage or limit torque transfer beyond a preset value.
At Dongguan Sango Hardware Fasteners Co., Ltd., we manufacture high-precision torque control screws to help our global clients ensure safe, repeatable, and error-proof assembly.
1. What Is a Torque Limiting Screw?
A Torque Limiting Screw is a fastener that features an integrated torque-limiting clutch mechanism. When the preset torque is reached, the screw slips, clicks, or disengages, preventing the user from overtightening it.
🔧 Main Benefits:
- Prevents damage to soft materials (plastic, aluminum)
- Eliminates tool dependency or guesswork
- Improves assembly repeatability
- Reduces training time for workers
- Enhances product safety and lifecycle
2. Types of Torque Limiting Screws
🔹 Preset Torque Breakaway Screw
- Disengages at a fixed torque (e.g., 0.6 Nm, 1.5 Nm)
- Clicks or free-spins once torque threshold is met
🔹 Re-engageable Torque Screw
- Allows repeated use with re-engagement after release
- Used in maintenance or field-serviceable products
🔹 One-Way Torque Screw (Tamper-Proof)
- Torque control in tightening direction only
- Common in consumer electronics and automotive sensors
🔹 Thumb-Screw Style Torque Limiting Screw
- Tool-free, ideal for manual fastening with torque control
- Used in medical devices, covers, and modules
3. Where Are Torque Limiting Screws Used?
- 🧪 Medical devices and lab instruments
- 📟 Consumer electronics and IoT enclosures
- 🔧 Assembly line jigs and fixtures
- 🚘 Automotive sensor modules and dashboard panels
- 🧰 Plastic housings and lighting enclosures
- 📦 Battery packs and smart devices
They are especially valuable where precision torque, operator-proofing, or lightweight materials are involved.
4. Typical Torque Ratings and Standards
| Torque Rating (Nm) | Application Example |
|---|---|
| 0.2–0.5 Nm | Micro-electronics, sensor housings |
| 0.6–1.2 Nm | Plastic panels, display modules |
| 1.5–2.5 Nm | Light fixtures, handheld medical devices |
| 3.0–5.0 Nm | Automotive components, equipment enclosures |
Tolerance: ±10% or better
Standards: Internal QC specs or customer-defined torque thresholds
5. Customization Options from Sango Hardware
We support:
- 📏 Thread sizes: M2 to M6, #4-40 to 1/4-20
- 🧩 Head types: pan, flat, hex socket, thumb screw, Torx
- 🛡 Torque range: 0.2Nm – 5Nm (±10%)
- ⚙️ Materials: stainless steel (SUS304/316), carbon steel, brass, aluminum
- 🧪 Finishes: black oxide, nickel, anodized, zinc plating
- 🛠 Clutch types: cam-over, ball detent, friction slip
Additional options:
- Color-coded heads for torque levels
- Laser-etched torque markings or logos
- One-time or multi-use torque settings
6. Case Study: Medical Device Housing with Torque-Controlled Screws
Client: European medical diagnostics equipment OEM
Problem: Field technicians overtightened screws, cracking housing during maintenance
Sango Solution:
- Supplied M3 × 10mm re-engageable torque screws (1.2 Nm preset)
- Stainless steel body, laser-marked torque value, anodized grip head
- Delivered with calibration certificate and torque test report
Result:
- Field service time reduced by 40%
- No cracking observed after 500+ access cycles
- Approved for global production lines
7. Why Choose Sango Hardware?
🛠 20+ Years of Fastener Expertise
- Precision thread rolling, micro-clutch assembly, spring tension control
🧪 Torque Testing In-House
- Calibrated digital torque testers with traceable results
📐 Custom Engineering Support
- Torque target validation, fit tests, and packaging kits
📦 Full OEM Service
- RoHS/REACH, ISO 9001 certified, barcode packs, English manuals
8. Conclusion: Controlled Torque = Controlled Quality
Torque Limiting Screws are essential in modern design—offering a foolproof way to ensure safety, consistency, and durability across production lines and field installations.
Work with Dongguan Sango Hardware Fasteners Co., Ltd. to create precision torque-controlled fastening solutions tailored to your products.