What Is Tensile Strength and Why Is It Important?

Tensile strength measures your hair's ability to stretch without breaking, contributing to its resilience and flexibility. Brittle hair prone to split ends or breakage may indicate weak tensile strength. The good news? With the right care, you can strengthen your hair from root to tip. 

Boosting your hair’s tensile strength is essential for maintaining healthy, resilient strands that can withstand daily wear and tear. Tensile strength refers to the hair’s ability to resist breakage when stretched or pulled, and improving it helps prevent split ends, breakage, and thinning. Stronger hair is less prone to damage from styling, brushing, and environmental stressors, resulting in healthier, fuller hair. Enhancing tensile strength through proper nutrition, hydration, and the use of strengthening treatments can promote long-term hair growth, reduce hair loss, and maintain a smooth, shiny appearance.

How Is Tensile Strength Measured?

Hair tensile strength is often measured using a Universal Testing Machine (UTM), which applies force to a hair strand until it breaks. If you don’t have access to specialized equipment (who even does?! LOL), you can assess your hair’s elasticity with a this DIY test:

The Stretch Test: Take a clean, dry strand of hair. Hold it between your fingers and gently stretch it. If it stretches and returns to its original length, your hair has good elasticity. If it snaps quickly, your hair may be brittle or damaged (*yikes).

Why Do Stylists Care About Tensile Strength?

Stylists test tensile strength to gauge hair’s ability to withstand treatments like coloring or heat styling. Hair with good tensile strength is less likely to break during these processes. A simple stretch test can guide them in choosing the best approach for your hair. 

What Affects Hair Tensile Strength?

Several factors can weaken your hair’s tensile strength:

1.  Heat Styling: Excessive use of curling irons or straighteners strips moisture from hair.

2.  Chemical Damage: Treatments like bleaching or coloring break down keratin bonds.

3.  Environmental Stressors: Sun, pollution, and hard water degrade the hair’s structure.

4.  Improper Care: Rough brushing, especially on wet hair, causes breakage (be kind to your locks, ladies).

How to Boost Hair’s Tensile Strength

1. Limit Chemical Damage

• Space out treatments like bleaching or coloring to give hair time to recover.
• Opt for gentler alternatives like semi-permanent color or ammonia-free dyes.

2. Be Gentle with Hair

• Use a wide-tooth comb on damp hair and detangle starting at the ends (read it again!!).
• Avoid rough towel-drying; gently pat hair instead.

3. Minimize Heat Damage

• Use Heat Protectant: Always apply before using hot tools (make sure to get every strand).
• Adjust Settings: Use the lowest effective heat on styling tools.
• Air-Dry: Let hair dry naturally or use a cool blow-dryer setting.

4. Hydrate and Protect from Environmental Stress

• Wear a hat or scarf to shield hair from UV rays.
• Use leave-in conditioners with UV filters.
• Rinse with filtered water to combat hard water effects.

5. Maintain a Balanced Diet

• Protein: Essential for keratin production. Include lean meats, eggs, and legumes.
• Iron and Zinc: Keep follicles healthy for stronger strands.
• Omega-3 Fatty Acids: Found in fish and nuts, these fats hydrate hair.
• Vitamins C and B: Boost collagen and keratin production for resilience.

6. Incorporate Strengthening Products

• Look for shampoos and treatments containing keratin, biotin, or collagen.
• Use a strengthening hair mask weekly for deep conditioning (just add it to your Sunday reset).
• Pro Tip: Apply a generous amount of hair mask to damp hair and leave it on for 10–15 minutes before rinsing.

7. Style with Care

• Avoid tight hairstyles that strain the hair shaft.
• Use fabric-covered hair ties to minimize damage (trust— you'll feel the difference).
• Opt for protective styles like loose buns or braids to reduce environmental exposure.

8. Focus on Scalp Care

• Healthy hair starts with a healthy scalp.
• Exfoliate Weekly: Use a scalp scrub or clarifying shampoo to remove buildup.
• Massage Regularly: Stimulates blood flow and delivers nutrients to follicles (put it on your partners to-do list, obviously).
• Limit Sun Exposure: Protect your scalp with hats or sunscreen.

9. Trim Regularly

• Split ends can weaken strands, reducing tensile strength. Schedule trims every six to eight weeks to maintain healthy hair.

10. Consider Supplements

• Hair-specific supplements containing biotin, silica, and vitamins A, C, and E can enhance hair’s tensile strength and thickness.

Final Thoughts

Building stronger hair starts with consistent TLC. By protecting your hair from damage, nourishing it from within, and using the right products, you can boost its tensile strength and enjoy healthier, more luxurious strands.