Spanner Nuts, Brass Spanner Nuts, Bronze Spanner Nuts and Stainless Steel Spanner Nuts
Precision Spanner Nuts: Brass, Bronze & Stainless Steel
We are one of the leading manufacturers and exporters of high-performance Spanner Nuts from India, supplying a diverse range of these critical precision fasteners to the global market for over three decades. Our extensive expertise lies in engineering Spanner Nuts that meet the most demanding applications across various heavy-duty industries. Also known as CWN Nuts or Capslock Wrenching Nuts, these specialized components are designed for situations where a standard hex nut is impractical, offering a low-profile, secure fastening solution. Our commitment to excellence is reflected in our rigorous quality control, adherence to international standards like ISO 9001, and our ability to provide customized spanner nut solutions with unmatched flexibility in production time. We understand that reliability and precision are paramount, which is why our Spanner Nuts are machined to exacting tolerances, ensuring a perfect fit and superior performance every time.
In-Depth Look at Spanner Nut Materials and Grades
Brass Spanner Nuts
Brass Spanner Nuts are highly sought after for their excellent corrosion resistance, particularly in marine, plumbing, and electrical applications where non-magnetic and non-sparking properties are critical for safety. The inherent lubricity of Brass allows for smooth installation and disassembly, reducing the risk of galling. We manufacture our Brass Spanner Nuts from high-grade materials conforming to ASTM B16 (Free Cutting Brass Rod), CZ121 / CW510L, BS 2874, and DIN 17660, ensuring consistent quality and performance. These nuts are ideal for use in potable water systems, fuel lines, and electrical connectors, providing long-lasting, reliable service without succumbing to dezincification when the correct alloy is specified.
Bronze Spanner Nuts
For applications requiring high strength, exceptional wear resistance, and superior corrosion resistance against seawater and chemicals, Bronze Spanner Nuts are the optimal choice. Commonly manufactured from Phosphor Bronze (ASTM B139, C51000) or Aluminum Bronze (DIN 17660, CA104), these nuts offer excellent anti-galling properties and high fatigue resistance. Their durability makes them a staple in marine engineering, shipbuilding, offshore oil rigs, and heavy industrial valve and pump manufacturing. The use of premium Bronze alloys ensures that our nuts can withstand high-load, high-stress environments, making them a robust and long-lasting fastening solution for demanding industrial applications.
Stainless Steel Spanner Nuts
When maximum corrosion resistance and high tensile strength are non-negotiable, our Stainless Steel Spanner Nuts are the definitive solution. We offer these in various grades to suit different environmental challenges, including AISI 304 / A2 for general corrosion resistance, AISI 316 / A4 for enhanced resistance to chlorides and acids, and AISI 316L for superior weldability. Our production conforms to international standards such as ASTM A276, DIN 934, and ISO 3506. These nuts are indispensable in the chemical processing industry, food and beverage machinery, pharmaceutical equipment, and architectural applications, providing a clean, hygienic, and maintenance-free stainless steel fastening component.
Manufacturing Excellence and Technical Specifications
Our Spanner Nuts are produced using state-of-the-art CNC machining centers and automatic lathes, ensuring dimensional accuracy and repeatability in every batch. The process begins with high-quality raw material rods, which are precisely machined to the required dimensions, after which the spanner holes (or slots) are drilled or milled. Secondary operations include deburring and thread tapping. We offer various plating and finishing options such as Passivation for Stainless Steel, Electropolishing, and Nickel Plating to further enhance corrosion resistance and aesthetic appeal.
Typical Spanner Nut Dimensions – Metric Thread (CWN Series)
The following table provides standard dimensions for a typical CWN Spanner Nut with metric threads. We specialize in customizing spanner nut dimensions to your specific technical drawings.
Line Drawing Representation: A simple 2D top and side view of a spanner nut, showing key dimensions: Outside Diameter (A), Height (B), Thread Size (C), and the diameter of the circle on which the spanner holes are pitched (D).
| Thread Size (C) | A (O.D.) mm | B (Height) mm | D (PCD) mm | No. of Holes | Hole Dia (mm) |
|---|---|---|---|---|---|
| M6 | 16 | 7 | 13.5 | 4 | 3.2 |
| M8 | 20 | 8 | 17.0 | 4 | 3.2 |
| M10 | 24 | 10 | 20.0 | 4 | 4.0 |
| M12 | 28 | 12 | 24.0 | 4 | 4.0 |
| M16 | 35 | 16 | 30.0 | 4 | 5.0 |
| M20 | 42 | 20 | 36.0 | 6 | 5.0 |
Typical Spanner Nut Dimensions – UNC Thread Series
For our customers in North America and for applications requiring Unified National Coarse threads, we offer a comprehensive range of UNC Spanner Nuts. The table below outlines standard dimensions for these imperial thread nuts.
| Thread Size (C) | A (O.D.) inches | B (Height) inches | D (PCD) inches | No. of Holes | Hole Dia (inches) |
|---|---|---|---|---|---|
| 1/4″-20 UNC | 0.625 | 0.275 | 0.531 | 4 | 0.126 |
| 5/16″-18 UNC | 0.750 | 0.315 | 0.625 | 4 | 0.126 |
| 3/8″-16 UNC | 0.875 | 0.354 | 0.750 | 4 | 0.157 |
| 1/2″-13 UNC | 1.125 | 0.433 | 0.938 | 4 | 0.157 |
| 5/8″-11 UNC | 1.375 | 0.551 | 1.125 | 4 | 0.197 |
| 3/4″-10 UNC | 1.625 | 0.630 | 1.313 | 6 | 0.197 |
Note: All dimensions are nominal and subject to standard machining tolerances. Custom sizes in both metric and UNC threads are available upon request.
Industries Served and Performance Metrics
Our Spanner Nuts are critical components in a wide array of industries, including Aerospace and Defense, Automotive Manufacturing, Marine and Shipbuilding, Oil and Gas Exploration, Heavy Engineering, Electronics and Telecommunications, and Railway Infrastructure. Key performance metrics we ensure include high tensile strength (varying by material grade), excellent shear strength, and reliable performance under vibration resistance. Our standard machining tolerances are maintained within ISO 2768-mK for general dimensions, with thread tolerances per ISO 965 for metric and ASME B1.1 for UNC.
Why Choose Our Spanner Nuts?
With over 30 years of global exposure and experience, we offer more than just a product; we offer a partnership. Our engineering support team is adept at analyzing your technical drawings and suggesting optimizations for both performance and cost-efficiency. We pride ourselves on our faster turnaround time of just 4-6 weeks, even for custom orders, ensuring your projects stay on schedule. Our customized packaging options, including branded boxes with your company’s logo, add value and streamline your inventory management. As a trusted manufacturer and exporter, we provide unparalleled customer support with clear, consistent communication at every step, from inquiry to delivery.
Customer Testimonials:
“We’ve been sourcing our Bronze Spanner Nuts for our offshore applications from this company for five years. The quality is consistently exceptional, and their ability to meet tight deadlines is impressive.” – David Miller, Engineering Procurement Manager, USA
“Their Brass Spanner Nuts are flawless and perfectly suited for our specialized electrical enclosures. The technical support and communication throughout the order process were outstanding.” – Sarah Chen, Project Lead, UK
Frequently Asked Questions (FAQ)
1. What is the primary advantage of a Spanner Nut?
Spanner Nuts provide a secure, low-clearance fastening solution where a standard wrench cannot fit, ideal for confined spaces in assembly design.
2. Can you supply Spanner Nuts in metric and imperial thread sizes?
Yes, we manufacture custom spanner nuts in both metric (ISO) and imperial (UN/UNC) thread standards to meet global customer specifications.
3. What is the typical lead time for a custom order?
Our standard turnaround time for custom and bulk orders is a reliable 4 to 6 weeks, depending on the order quantity and specific requirements.
4. Do your Brass Spanner Nuts resist dezincification?
We offer dezincification-resistant brass alloys like CW510L for applications involving potable water or specific corrosive environments.
5. What finishes are available for Stainless Steel Spanner Nuts?
We offer passivation for maximum corrosion resistance, as well as electropolishing for a clean, hygienic finish.
6. Are your manufacturing processes certified?
Our facility is ISO 9001:2015 certified, ensuring consistent quality management and adherence to standardized manufacturing processes.
7. Can you provide material certification?
Yes, we supply full material traceability and certification (3.1 Mill Certificate) with all our shipments for quality assurance.
8. What is the maximum temperature your Spanner Nuts can withstand?
This depends on the material; Bronze and Stainless Steel Spanner Nuts generally offer higher temperature resistance than Brass.
9. Do you provide samples for evaluation?
We can provide samples for qualified projects to help you verify fit, form, and function before placing a bulk order.
10. How do I specify a custom Spanner Nut?
Simply provide us with your technical drawing detailing thread size (e.g., M12 or 1/2″-13 UNC), O.D., height, hole PCD, and material specification for a prompt quote.
11. What packaging options do you offer?
We provide customized packaging solutions including vacuum-sealed bags, poly bags, and boxes with your company’s labels and logo.
12. Are your nuts suitable for high-vibration environments?
Yes, when properly torqued, the design and precise manufacturing of our nuts offer excellent vibration resistance.
13. What is the difference between CWN and Spanner Nuts?
They are often used interchangeably; CWN typically refers to the standardized “Capslock Wrenching Nut” series with specific dimensions.
14. Can you manufacture Spanner Nuts from other materials like Aluminum?
Absolutely, we can produce precision spanner nuts from Aluminum, Alloy Steel, and other engineering materials upon request.
15. What are your payment terms for new international customers?
We offer flexible terms, typically a 50% advance with balance before shipment, ensuring a smooth and secure transaction for all parties.
Glossary of Terms
CWN Nut:Â Stands for “Capslock Wrenching Nut,” a common standardized type of Spanner Nut.
UNC (Unified National Coarse):Â A standard thread type with a defined number of threads per inch, widely used in the United States and Canada.
PCD (Pitch Circle Diameter):Â The diameter of the circle on which the spanner holes are located.
Galling:Â A form of wear caused by adhesion between sliding surfaces, common in stainless steel and aluminum fasteners.
Tensile Strength:Â The maximum stress a material can withstand while being stretched before failing.
Passivation:Â A chemical process for Stainless Steel that removes free iron and enhances the natural chromium oxide layer for corrosion resistance.
Dezincification:Â A form of corrosion in Brass where zinc is leached out, leaving a porous copper structure; prevented by using specific alloys.
Non-Magnetic:Â A property of materials like Brass and certain Stainless Steels that prevents them from being magnetized.
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Updated: 2025
Ready for a Precision Quote?
Leverage our three decades of manufacturing expertise for your next project. Contact our engineering sales team today to discuss your Spanner Nut requirements in metric or UNC thread, request a comprehensive brochure, or ask for a competitive quote.
Email: sales@conexscrews.com | Phone/WhatsApp: +91 22 43449300
