rachel_melton
rachel_melton Jan 23, 2026 β€’ 0 views

Grade 5 vs Grade 8 Bolts: Choosing the Right One for Your Project

Hey everyone! πŸ‘‹ Ever wondered which bolt to use for your DIY project? πŸ€” Grade 5 or Grade 8? It can be confusing! Let's break it down in a way that's super easy to understand!
πŸ”¨ Home Improvement & DIY

1 Answers

βœ… Best Answer

πŸ”© What is a Grade 5 Bolt?

A Grade 5 bolt is a medium-strength fastener commonly used in automotive and construction applications. It's made from medium carbon steel and is heat-treated to increase its strength.

βš™οΈ What is a Grade 8 Bolt?

A Grade 8 bolt is a high-strength fastener designed for demanding applications requiring significant clamping force. It's made from alloy steel and undergoes a more rigorous heat-treating process than Grade 5 bolts.

πŸ†š Grade 5 vs. Grade 8 Bolts: The Key Differences

Feature Grade 5 Bolt Grade 8 Bolt
Material Medium Carbon Steel Alloy Steel
Tensile Strength Lower (approx. 120,000 PSI) Higher (approx. 150,000 PSI)
Yield Strength Lower (approx. 92,000 PSI) Higher (approx. 130,000 PSI)
Ductility More Ductile Less Ductile
Cost Less Expensive More Expensive
Applications General Purpose, Automotive Repair, Light Construction High-Stress Applications, Heavy Machinery, Suspension Systems

πŸ”‘ Key Takeaways

  • πŸ’ͺ Strength: Grade 8 bolts are stronger than Grade 5 bolts.
  • πŸ’° Cost: Grade 5 bolts are more affordable.
  • πŸ”© Application: Choose based on the stress the bolt will endure. For high-stress applications, opt for Grade 8.
  • ⚠️ Ductility: Grade 5 bolts offer more flexibility before breaking.
  • πŸ” Identification: Grade 5 bolts typically have three radial lines on the head, while Grade 8 bolts have six.

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