Marine Thumb Screw

About product

A marine thumb screw is a one-piece screw with large flattened heads and external machine screw thread. It is designed for easy hand tightening and loosening without the need for tools. This versatile fastener is commonly used in marine applications that require frequent adjustments or disassembly. Thumb screws offer convenience and quick access while ensuring a secure connection.

Marine Thumb Screw Drawing

Additional information


marine fastener


stainless steel, nylon, etc.

Product Detail

Types and Specifications Of Marine Thumb Screw

  • Type A: Type A thumb screws, also known as Type S (Shoulder), feature a shoulder under the head, which has a slightly smaller diameter than the head width. This type is used when the shoulder contacts a mating surface, providing stability and support.
  • Type B: Type B thumb screws, also referred to as Type P (Plain), do not have a shoulder. Instead, the tip of the screw contacts the mating surface, similar to a set screw. Type B thumb screws are commonly used as compression fasteners.

Thumb screws are available in various thread specifications, typically measured in the number of threads per inch. They primarily follow the standard right-hand threads and Unified inch coarse series (UNC), with some sizes available in Unified inch fine series (UNF). The diameter sizes range from #6 to 3/8″, and lengths start at 1/4″ and go up to approximately 6″, with longer lengths found in larger sizes.

Materials and Usage Considerations Of Marine Thumb Screw

Thumb screws are commonly made from steel or stainless steel materials. Steel thumb screws are often zinc plated to enhance corrosion resistance. The head dimensions of thumb screws are generally standardized, although the specific contour of the head may vary among manufacturers.

These screws are typically used with internally threaded (tapped) holes, but they can also be paired with nuts if required. Thumb screws are versatile and widely used in marine applications where quick adjustments, disassembly, and finger pressure torque are sufficient for tightening and loosening tasks.

To ensure specific requirements are met, reference to the American Society of Mechanical Engineers Standard ASME B18.6.8 Thumb Screws and Wing Screws (Inch Series) can provide detailed specifications related to thumb screws.

Marine Thumb Screw Size Chart

Know Who We Are

About our company

Zava Marine Corporation is a leading supplier of marine parts and components. With a strong focus on quality and customer satisfaction, we specialize in providing a comprehensive range of high-quality marine equipment and accessories. Our products include deck equipment, ship accessories, and various other essential components needed for smooth maritime operations.

With a global presence, we serve a diverse customer base, including shipbuilders, shipowners, offshore operators, and marine equipment distributors. We are committed to providing exceptional service and tailored solutions to meet our customers’ unique needs.


Zava Marine offers a comprehensive range of certifications for marine parts in accordance with international standards and regulations. These certifications include those provided by renowned marine classification societies such as Lloyd’s Register (LR), Bureau Veritas (BV), China Classification Society (CCS), Registro Italiano Navale (RINA), American Bureau of Shipping (ABS), Nippon Kaiji Kyokai (NK), and Det Norske Veritas – Germanischer Lloyd (DNV-GL). By collaborating with these esteemed societies, Zava Marine ensures that our certified marine parts meet the highest standards of safety, quality, and performance, instilling confidence in our reliability and compliance within the maritime industry.

The warranty provided by Zava Marine covers defects in materials and workmanship for a period of two years from the date of purchase. During this warranty period, if any marine parts purchased from Zava Marine exhibit issues or failures resulting from manufacturing defects or faulty materials, Zava Marine will take responsibility for repair or replacement of the affected parts. 

Zava Marine has recently opened new molds for European and North American clients, utilizing materials such as metal, ABS, PVC, and more. These successful mold opening projects allow us to provide customized marine parts and components that meet the specific requirements of our clients in these regions.

Typically, Zava Marine can ship samples within 7 days once the product drawing has been mutually confirmed by both parties. This efficient process ensures that customers can receive samples promptly, allowing them to assess the quality and suitability of the products.

Zava Marine frequently utilizes a wide range of materials in our projects. These materials include aluminum, stainless steel, carbon steel, copper, plastics, titanium, and PEEK (Polyether Ether Ketone). Each material offers unique properties and characteristics suitable for various marine applications. 

Yes, we provide customization services for marine parts. We understand that every project and application may have unique requirements, and we are committed to delivering tailored solutions. By collaborating closely with our clients, we can adapt our products to specific specifications, ensuring optimal fit, performance, and compatibility. Whether it’s modifying existing designs or creating entirely new parts, our customization services cater to the diverse needs of the maritime industry.

Absolutely! We offer product design and development services to support our clients’ needs. Our experienced team of engineers and designers can collaborate with clients from concept development to final product realization. By leveraging our expertise in marine engineering and design, we can provide valuable insights and innovative solutions. Whether it’s optimizing existing designs or creating entirely new products, we are equipped to assist clients in bringing their ideas to life efficiently and effectively.

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Zava Marine