Katran Elasticity Standard (KES-50) — The New Benchmark for Fishing Line Stretch

For over a decade, I have studied and tested how monofilament fishing lines behave under tension. What I discovered was both surprising and frustrating: there is no global standard for measuring the stretch (elasticity) of fishing lines. Each manufacturer uses their own method, often without explaining key test conditions, such as the applied load or procedure.
This lack of transparency makes it impossible for anglers to compare lines across brands. That’s why I developed the Katran Elasticity Standard (KES-50) — a clear, fair, and repeatable benchmark for the industry.

📊 What is KES-50? KES-50 stands for Katran Elasticity Standard at 50% Breaking Strength. It measures how much a fishing line stretches when subjected to 50% of its rated breaking strain.
This benchmark reflects the typical load lines face during casting, fighting carp, and fish runs.

• Why 50% Load? It simulates real fishing situations.
• It avoids inaccurate readings near the breaking point, where lines behave unpredictably.
• It provides repeatable and fair results.

🧪 The KES-50 Testing Method to measure stretch using KES-50:

1. Cut a 10-meter sample of monofilament or fluorocarbon line.
2. Apply a load equal to 50% of the line’s rated breaking strength (for example, 10 lb for a 20 lb line).
3. Measure the increase in length.
4. Calculate the stretch percentage using this formula:
5. "Stretch percentage equals the elongation in centimetres divided by the original length in centimetres, multiplied by 100."

Example:
If a 10-meter line stretches by 1 meter under 50% load, the stretch percentage is 10%.
If it stretches by 1.5 meters, the stretch percentage is 15%.
The results are proportional for longer lines:
A 100-meter line with 10% stretch will elongate by 10 meters under 50% load.

• Important: Always use longer samples (10 meters or more) for accurate results. Short 1-meter tests are unreliable due to clamping errors.

📌 Stretch Classifications for Fishing LinesUsing KES-50, fishing lines can be categorized as:

• Very Low Stretch: up to 10%
• Low Stretch: 10% – 15%
• Medium Stretch: 15% – 20%
• High Stretch: over 20%

This helps anglers choose the right mainline for their style: long-distance casting, snag fishing, or zig rigs.

• 🎣 Real-World Example: Katran Synapse Wild Carp
• Diameter: 0.365 mm
• Breaking Strength: 20.5 lb
• KES-50 Test Load: 10.25 lb
• Measured Stretch: 12%

This means:

If you cast 100 meters with Synapse Wild Carp, the line will stretch up to 12 meters under maximum pressure. This information is crucial for casting accuracy, fish safety, and bite detection.

💡 Why the Carp Fishing Industry Needs KES-50Adopting KES-50 will:

1. Set a fair and consistent benchmark for all brands.
2. Help anglers make informed decisions with clear, comparable data.
3. Increase trust and transparency across the fishing tackle industry.
4. Support magazines, YouTubers, and retailers in testing and comparing lines fairly.
5. Lay the foundation for future ISO-level standards in tackle manufacturing.

🌍 A Call for Global Collaboration
As the founder of Katran GmbH, I invite:

• Manufacturers
• Test laboratories
• Distributors
• Carp anglers