M3 Hex Bolt: Precision Fastening for Demanding Industrial Applications
In the intricate world of precision engineering and assembly, the reliability of every component is paramount. The M3 hex bolt stands as a fundamental yet critical fastener, designed to deliver secure, robust, and repeatable clamping force in compact and high-stress environments. Engineered to exacting standards, our M3 hex bolts are the preferred choice for OEMs and MRO professionals across industries where dimensional accuracy, material integrity, and consistent performance are non-negotiable. This product page details the specifications, advantages, and applications of our premium-grade hex bolts.
Product Overview
Our M3 hex bolt is a metric, externally threaded fastener characterized by its hexagonal head, which allows for high-torque application with standard wrenches or socket sets. Defined by a 3mm nominal diameter and a fine or coarse thread pitch, it is a versatile solution for creating strong, mechanical joints in metal, plastic, and composite assemblies. Manufactured from high-grade materials and subjected to rigorous quality control, each bolt ensures optimal tensile strength, corrosion resistance, and dimensional conformity for seamless integration into your production line or maintenance schedule.
Key Features
- High-Strength Materials: Available in stainless steel (A2-70, A4-80), alloy steel (grade 8.8, 10.9, and 12.9), and brass to meet diverse environmental and load-bearing requirements.
- Precision Threading: Rolled threads for superior strength and smoother engagement, reducing the risk of cross-threading and ensuring consistent clamping force.
- Durable Hex Head: Clean, sharp edges on the hexagonal head provide excellent wrench grip, preventing tool slippage and head rounding during installation.
- Multiple Finishes: Options include plain, zinc-plated, hot-dip galvanized, and dichromate finishes for enhanced corrosion protection and aesthetic appeal.
- Full Size Range: Comprehensive inventory of standard lengths and thread pitches (e.g., M3x0.5, M3x0.35) to suit any design specification.
Technical Specifications
| Parameter | Specification | Details / Standards |
|---|---|---|
| Nominal Diameter (d) | 3 mm | Metric (M3) |
| Standard Thread Pitch | 0.5 mm (Coarse) | Alternative: 0.35 mm (Fine) available |
| Head Style | Hexagon (Hex) | ISO 4014 / 4017, DIN 933 / 931 |
| Common Lengths (L) | 5mm - 50mm | Measured from under-head to tip |
| Strength Grades (Steel) | 8.8, 10.9, 12.9 | ISO 898-1 Compliant |
| Stainless Steel Grades | A2-70, A4-80 | AISI 304 / 316 equivalents |
| Common Finishes | Zinc Plated, Plain, HDG | Corrosion resistance varies by finish |
| Drive Type | Hex Key / Wrench | Standard 2.5mm hex key size |
Application Scenarios
The versatility of the M3 hex bolt makes it indispensable in a wide array of sectors. Its small size and high strength are ideal for applications where space is limited but performance is critical.
- Electronics & Telecommunications: Securing PCBs, heat sinks, chassis components, and server racks where vibration resistance is crucial.
- Automotive & Aerospace: Interior trim, sensor mounting, avionics housings, and non-critical structural assemblies requiring lightweight, reliable fasteners.
- Industrial Machinery: Panel fastening, guard assembly, and component mounting on CNC machines, conveyors, and robotic arms.
- Medical Equipment: Assembly of diagnostic devices, imaging systems, and surgical tools, often requiring stainless steel for sterilization compatibility.
- Consumer Goods & Furniture: High-end appliance assembly, bicycle components, and modular furniture where a clean, professional finish is desired.
Advantages
Choosing our M3 hex bolt provides tangible benefits that enhance your product quality and operational efficiency.
- Superior Load Distribution: The hexagonal head design offers a large bearing surface, distributing clamp load effectively and minimizing surface damage.
- Optimized for Automation: Consistent dimensions and reliable threading allow for trouble-free use in automated screw-driving systems, increasing assembly line speed.
- Enhanced Durability: Manufactured from controlled materials, our bolts resist shear, tensile stress, and fatigue, ensuring long-term joint integrity.
- Global Compliance: Products are manufactured to international standards (ISO, DIN, ASTM), ensuring acceptance in global supply chains.
- Cost-Effective Inventory: Bulk availability and competitive pricing reduce per-unit costs and simplify procurement for large-scale projects.
Why Choose Us
As a specialist supplier in the industrial fastener market, we distinguish ourselves through commitment to quality and customer partnership.
- Direct Manufacturer & Exporter: We control the manufacturing process from raw material to finished product, ensuring quality and enabling competitive pricing.
- Rigorous QC Protocols: Every batch undergoes testing for dimensions, thread accuracy, hardness, and coating thickness, backed by full traceability.
- Extensive Inventory: We maintain a large stock of standard M3 hex bolts in various grades and finishes, ready for prompt shipment.
- Technical Support: Our engineering team can assist with material selection, specification review, and custom requirements for specialized applications.
- Global Logistics Expertise: We facilitate smooth international trade with reliable packaging, comprehensive documentation, and efficient shipping solutions.
FAQ
What is the difference between an M3 hex bolt and a screw?
While often used interchangeably, a M3 hex bolt is typically designed to be used with a nut or in a tapped hole to clamp parts together, and is driven by a wrench on its hexagonal head. An M3 hex *screw* is often intended to be driven directly into a pre-tapped hole or a softer material without a nut.
What does the strength grade (e.g., 8.8 or 10.9) mean on a steel M3 hex bolt?
The grade indicates the bolt's mechanical properties. For an 8.8 grade, the first number (8) multiplied by 100 gives the minimum tensile strength in MPa (800 MPa). The product of the two numbers (8 x 8 = 64) indicates 10% of the yield strength in MPa (640 MPa). Higher grades like 10.9 and 12.9 offer greater strength for more demanding applications.
Which material should I choose for outdoor or corrosive environments?
For excellent corrosion resistance, we recommend A4-80 (316 stainless steel) M3 hex bolts. For highly corrosive environments (e.g., marine, chemical), or where chlorides are present, A4-80 is superior to standard A2-70 (304 stainless). Hot-dip galvanized alloy steel is also a robust, cost-effective option for many outdoor applications.
Can you supply M3 hex bolts with non-standard lengths or special threads?
Yes. We specialize in providing custom fastener solutions. We can manufacture M3 hex bolts to your exact specifications, including non-standard lengths, special thread pitches, unique head markings, and proprietary coatings. Contact our sales team with your drawings or specifications for a quote.
What is your minimum order quantity (MOQ) and packaging?
We offer flexible MOQs to suit both small prototyping needs and large-volume production runs. Standard packaging is in labeled, sealed poly bags within sturdy cartons. Bulk packaging in boxes or drums is available for high-volume orders to optimize your handling and storage.
