The Fastener Breakdown: Choosing the Right Bolt, Nut, or Screw for Industrial Applications
TOOLING & MACHINING
Fasteners are everywhere in manufacturing—holding together machines, structural assemblies, conveyor systems, and custom fixtures. Yet they’re often treated as afterthoughts in procurement. Choosing the wrong fastener may lead to premature failure, safety hazards, or increased maintenance downtime
Why Fastener Selection Matters
The right fastener doesn’t just hold parts together—it ensures proper load distribution, resists vibration loosening, and holds up to temperature and environmental conditions. Using substandard or mismatched fasteners can lead to:
Thread stripping
Fatigue failure
Galvanic corrosion
Leaks (in pressure or fluid systems)
Compliance issues with safety standards
Key Types of Fasteners
1. Bolts
Used where high clamping force is needed. Typically paired with nuts and washers.
Common types:
Hex bolts
Carriage bolts
Flange bolts
Socket head bolts
2. Screws
Used in tapped holes without a nut. Self-threading options are great for sheet metal or soft materials.
Types include:
Machine screws
Self-tapping screws
Wood screws
Sheet metal screws
3. Nuts
Threaded fasteners used with bolts to clamp materials together.
Popular varieties:
Hex nuts
Lock nuts (nylon insert, jam nuts)
Flange nuts
Wing nuts
4. Washers
Distribute load, protect surfaces, and prevent loosening.
Types include:
Flat washers
Lock washers
Belleville washers
Fender washers
Understanding Fastener Grades and Strength
Fasteners are graded based on their tensile strength. Using the wrong grade could compromise safety.
Grade 2: Low strength, general-purpose use (not for load-bearing)
Grade 5: Medium strength, automotive or structural applications
Grade 8: High strength, used in demanding industrial settings
Stainless Steel (A2/A4): Corrosion-resistant, lower strength
Metric Classes: Common classes are 8.8, 10.9, and 12.9 (10.9 roughly equals Grade 8)
Tip: Don’t mix grades or thread types (coarse vs. fine). Always match to application specs.
Material Matters: When to Go Beyond Steel
Depending on the environment, material choice can make or break fastener performance.
Carbon Steel: Strong and cost-effective; must be coated for corrosion resistance.
Stainless Steel: Ideal for wet or corrosive environments (but softer than carbon steel).
Brass: Corrosion-resistant, used in plumbing and electrical.
Titanium: Lightweight and strong; often used in aerospace.
Nylon/Plastic: Great for electrical insulation or non-load-bearing fixtures.
Coatings & Finishes
Fastener coatings provide corrosion protection and sometimes lubricity for installation.
Zinc-Plated: General corrosion resistance for indoor use.
Hot-Dip Galvanized: Superior protection for outdoor or wet environments.
Black Oxide: Appearance-oriented; mild protection.
PTFE/Anti-Seize Coatings: Help prevent galling and facilitate reuse.
Fastener Selection Tips
Start with the Application
Is it structural? Is there vibration? Is it exposed to chemicals or water?Verify Load Requirements
Match tensile and shear strength to operating forces.Choose the Right Threads
Fine threads hold better under vibration; coarse threads are faster to install and better for softer materials.Don’t Forget Washers
Proper washers prevent surface marring, distribute load, and reduce loosening.Keep an Eye on Compliance
Fasteners in regulated industries (aerospace, medical, construction) must meet specific codes and certifications.
Inventory Tips for Procurement Teams
Standardize fastener types across machines to reduce SKUs.
Store fasteners in labeled, humidity-controlled bins to prevent rust.
Track usage by project or department for forecasting and reordering.
Always order extra: fasteners are cheap, downtime isn’t.
Final Thoughts
Whether you’re securing a conveyor frame or assembling high-precision tooling, fasteners matter. Understanding grades, materials, and applications can improve machine performance, worker safety, and your bottom line.
At Ironridge Supply Co., we stock an extensive range of industrial fasteners and hardware, including Grade 8 bolts, stainless steel options, nylon-insert lock nuts, and more. Our product experts can help you spec the right fastener every time.
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