Semi-Rigid Coax Cable (Micro-Coax) vs. Hand-Formable Coax Cable (MaxForm): What’s the Difference?
Posted by Tek-Stock LLC. on 18th Mar 2026
Semi-Rigid Coax Cable vs. Hand-Formable Coax: What’s the Difference?
When selecting coaxial cable for RF and microwave applications, engineers and buyers often compare semi-rigid coax cable (Micro-Coax) and hand-formable coax cable (Thermax MaxForm). While both offer excellent electrical performance, they differ significantly in flexibility, installation, and long-term use.
Understanding these differences can help you choose the right cable for your specific application.
What is Semi-Rigid Coax Cable?
Semi-rigid coax cable features a solid outer conductor, typically made of copper or aluminum, which provides excellent shielding and stable electrical performance.
Because of its rigid construction, semi-rigid cable must be formed using tools and is intended for permanent installations where precise routing and minimal signal loss are critical.
Common examples include:
- UT-085 (RG405)
- UT-141 (RG402)
These cables are widely used in aerospace systems, radar, RF modules, and high-frequency test environments.
What is Hand-Formable Coax Cable (Thermax MaxForm)?
Hand-formable coax cable, often referred to as Thermax MaxForm, is designed to provide similar electrical performance to semi-rigid coax while allowing the cable to be bent and shaped by hand.
Unlike semi-rigid cable, Thermax MaxForm can be:
- Bent without tools
- Adjusted after installation
- Re-formed multiple times
This makes it ideal for prototyping, testing, and applications where routing may need to change.
Key Differences Between Semi-Rigid and Hand-Formable Coax
| Feature | Semi-Rigid Coax | Hand-Formable Coax (MaxForm) |
|---|---|---|
| Flexibility | Very low | High (hand-formable) |
| Installation | Requires tools | No tools required |
| Reusability | Limited | Can be re-formed multiple times |
| Mechanical Stability | Very high | High |
| Shielding | Excellent | Excellent |
| Best Use Case | Permanent installations | Prototyping and adjustable routing |
When to Use Semi-Rigid Coax Cable
- Maximum shielding and mechanical stability are required
- The cable will remain fixed after installation
- High-frequency performance consistency is critical
- Used in aerospace, radar, and production RF assemblies
When to Use Hand-Formable Coax Cable
- Quick routing is needed without tools
- Designs may change during development
- Ideal for lab, test, and prototype environments
- Frequent adjustments or rework are required
Which One Should You Choose?
For permanent, high-performance installations, semi-rigid coax cable is typically the best choice. For flexible routing, prototyping, and applications requiring adjustment, hand-formable coax provides a more efficient solution.
Many engineers use both: semi-rigid coax for final production assemblies and hand-formable coax for testing and development.
Explore Your Options
Final Thoughts
Both semi-rigid and hand-formable coax cables offer excellent RF performance. The right choice depends on your need for flexibility, installation method, and long-term stability.
Understanding these differences will help improve system reliability, simplify installation, and optimize your overall RF design.