Self-Tapping Inserts for Aluminum and Plastics – Strong Threads Without Pre-Tapping
When working with low-strength materials like aluminum, thermoplastics, composites, or even wood, traditional threading methods often fail—causing stripped threads, loose joints, or premature failure.
The solution? Self-Tapping Inserts.
At Dongguan Sango Hardware Fasteners Co., Ltd., we manufacture and export a wide range of self-tapping threaded inserts designed for high-strength, repeatable fastening without the need for pre-tapping or adhesive.
1. What Is a Self-Tapping Insert?
A Self-Tapping Insert is a cylindrical metal bushing with cutting flutes or threads designed to cut its own internal thread as it’s driven into a base material. Once installed, it provides a metal thread interface for machine screws in materials that normally wouldn't support threading.
🧩 Core Advantages:
- No need to tap or pre-thread holes
- High pull-out and torque resistance
- Creates reusable, wear-resistant threads
- Suitable for post-molding installation
- Ideal for field repair or retrofits
2. Common Types of Self-Tapping Inserts
🔹 Slotted Insert (Straight Flute)
- Cuts thread into plastic or soft metals
- Allows material flow during installation
- Typically used in thermoplastics, ABS, PP
🔹 Threaded Insert with Cutting Holes
- Multiple axial holes aid chip removal
- Offers better grip and reduced stress on material
🔹 Hex Drive Insert
- Driven with Allen key or hex driver
- Easy to control installation depth and torque
🔹 Self-Tapping Insert with External Knurling
- Knurled surface increases friction
- Prevents rotation or pull-out in soft materials
🔹 Closed-End Insert
- Prevents screw intrusion into hollow base
- Ideal for electrical components or fluid-sensitive assemblies
3. Applications of Self-Tapping Inserts
Self-tapping inserts are essential in:
- 🔩 Aluminum component mounting
- 🖥️ Plastic enclosures for electronics and displays
- 🛠 3D printed prototypes and production parts
- 📦 Consumer electronics with removable panels
- 🪵 Wood furniture and flat-pack assembly
- 🧪 Medical device housing and lab equipment
They’re also widely used in aftermarket repair, field retrofitting, and OEM contract manufacturing.
4. Choosing the Right Insert
| Base Material | Recommended Insert Type | Installation Tool |
|---|---|---|
| ABS, PC, Nylon | Slotted or hole-style insert | Electric screwdriver or press-in tool |
| Cast aluminum | Spiral cutting insert or knurled | Hand driver or power drill |
| MDF, plywood | Coarse-thread wood insert | Hex driver or T-handle wrench |
| 3D printed parts | Fine knurl or slotted insert | Manual press-in or thread-in |
| Glass-filled plastic | Self-tapping with chip holes | Controlled torque tool |
Thread sizes available: M2 to M12, UNC/UNF, custom internal threads
Length options: 4mm to 25mm standard, custom on request
5. Custom Options from Sango Hardware
We offer:
- 📏 Metric & inch sizes
- ⚙️ External threads: straight, tapered, knurled, chip-relief
- 🔧 Drive features: slot, hex socket, cross recess
- 🔩 Materials: brass, stainless steel (SUS303/304), carbon steel, aluminum
- 🧪 Surface finishes: nickel, passivation, black oxide, zinc, RoHS plating
OEM options: engraved batch numbers, color-coded rings, multi-cavity packaging, torque testing reports
6. Case Study: Fastening Inserts for Aluminum Enclosure Retrofit
Client: UK-based industrial display system integrator
Problem: Screws in cast aluminum enclosures frequently stripped due to repeated maintenance cycles
Sango Solution:
- Designed M5 self-tapping inserts with internal M5x0.8 thread and spiral cutting flutes
- Delivered pre-packed kits with 100 inserts + T-handle driver
- Each insert tested for >12Nm pull-out resistance
Result:
- Strip rate reduced from 8.3% to <0.5%
- Assembly team reduced installation time by 30%
- Inserts added to all product BOMs for export builds
7. Why Choose Sango Hardware for Self-Tapping Inserts?
🛠 Factory-direct manufacturing
- Over 60 precision machines including CNC, tapping, knurling, and automatic packaging
🧪 Full testing included
- Salt spray, pull-out force, thread accuracy, burr inspection
📐 Fast prototyping support
- Custom drawings, CAD files, thread matching services available
📦 Export-ready logistics
- RoHS/REACH documents, barcodes, blister packaging, English labels
8. Conclusion: Strong Threads. No Tapping. No Glue.
If you need fast, reliable threaded connections in plastics, aluminum, or soft materials—Self-Tapping Inserts are your answer.
Contact Dongguan Sango Hardware Fasteners Co., Ltd. to get started with custom-cut, field-ready inserts that make your products stronger, smarter, and easier to assemble.