Screws, Bolts, Nuts & Washers: A Complete Fastener Guide
Unsure how to choose the right fastener?
Fasteners vary in type, thread, head, and function. This guide covers the differences between screws, bolts, nuts, and washers with real-world examples.
Avoid costly assembly issues. Understand fastener types before you order.
🧭 Table of Contents
- Introduction
- Differences Between Screws and Bolts
- Choosing the Right Nut Type
- Washer Roles: Flat, Spring, Cup Types
- Common Mistakes in Fastener Selection
- FAQs
- Conclusion & Contact
Introduction
Fasteners are essential for any mechanical assembly, yet many buyers confuse the roles of screws, bolts, nuts, and washers. At Prime, we’ve encountered this confusion from global clients across industries—from OEMs to maintenance engineers. This guide clarifies their key differences, correct applications, and how to avoid selection mistakes. Whether you’re sourcing for construction, electronics, or heavy machinery, making the right fastener decision starts here.
Key industry resources:
Differences Between Screws and Bolts
Many confuse screws and bolts. They differ in structure and how they’re installed.
Screws create their own thread in a material. Bolts require a nut to secure. Their usage depends on joint type and load.
| Feature | Screw | Bolt |
|---|---|---|
| Thread Type | Tapered, self-tapping | Straight, machine-cut |
| Installation | Drives into base material | Requires nut on opposite side |
| Tool Required | Screwdriver or drill | Wrench or socket |
| Common Use | Wood, plastics, sheet metal | Machinery, steel assemblies |
When to choose:
- Use screws for one-side access and softer materials.
- Use bolts when strength and secure fastening are critical.
More references:
Choosing the Right Nut Type
Nuts secure bolts, but using the wrong type can cause failure.
Hex nuts are standard. Lock nuts prevent loosening. Wing nuts allow hand tightening.
| Nut Type | Primary Use | Advantages | Common Application |
|---|---|---|---|
| Hex Nut | General assembly | Easy to install, versatile | Machinery, brackets, automotive |
| Lock Nut | Anti-loosening | Resists vibration and rotation | Engines, moving equipment |
| Wing Nut | Tool-free applications | Quick hand adjustments | Electrical panels, light fixtures |
When to use:
- Use lock nuts in vibrating machines.
- Use wing nuts for fast, tool-free tasks.
Helpful links:
Washer Roles: Flat, Spring, Cup Types
Washers do more than fill space.
Flat washers spread load. Spring washers resist loosening. Cup washers seal or cushion.
| Washer Type | Function | Best For |
|---|---|---|
| Flat Washer | Load distribution | Almost all bolted joints |
| Spring Washer | Shock absorption, anti-loosening | Vibrating machines, motors |
| Cup Washer | Sealing, aesthetics | Decorative/precision electronics |
Tips:
- Always combine spring washers with flat washers on soft surfaces.
- Use cup washers for finishes in electrical enclosures.
Resources:
Common Mistakes in Fastener Selection
Incorrect fastener choice causes failures and extra cost.
Common errors include wrong threading, missing washers, poor coatings, and improper tightening.
| Mistake | Effect | How to Prevent |
|---|---|---|
| Wrong thread type | Stripping, misalignment | Match ISO or UNC threads |
| Missing washers | Damage, loosening | Always use flat or lock washers |
| Wrong coating or material | Rust, breakage | Choose based on environmental factors |
| Over/under-tightening | Bolt failure | Use proper torque tools |
| Ignoring vibration | Loosening, system failure | Add lock nuts or spring washers |
Reference tools:
FAQs
1. What’s the difference between a screw and a bolt?
A screw cuts its own thread. A bolt needs a nut or threaded hole.
2. Can I mix imperial and metric fasteners?
No. Always use the correct standard to prevent stripping or breakage.
3. Are all nuts compatible with all bolts?
Only if thread type, pitch, and diameter match.
4. Which washers prevent loosening?
Spring washers and Nord-Lock wedge washers.
5. Best surface treatment for outdoor fasteners?
Hot-dip galvanized or 316 stainless steel.
6. Where to source reliable fasteners?
From certified factories like Prime.
Conclusion & Contact
Choosing the right fastener is critical to your assembly’s strength and durability. At Prime, we simplify the process with expert support and ISO-certified production.
📩 Contact us for:
- Custom fastener solutions
- CNC-machined bolts, screws, nuts & washers
- Fast delivery & stable supply
🌐 Website: https://primecustomparts.com
✉️ Email: [email protected]
Let’s build your perfect assembly—one fastener at a time.
