What are Sealing Screws With O-Rings?

Sealing screws, sometimes referred to as o ring screws, are precision machine fasteners equipped with an integrated O-ring just beneath the screw head. These specialist fasteners are designed to form a secure, leak-tight seal between the fastener and its mating surface, ideal for applications where you need to keep fluids, gases or contaminants either contained or excluded.

Unlike sealing roofing screws, a screw with an o ring is all about precision and consistent sealing performance. The rubber seal (Buna, Flurosilicone, Silicone or Viton) is compressed against the surface, helping these rubber seal screws maintain a tight, reliable fit. Sealing screws are often referred to by brand names like Zago screws or Zago sealing screws.

How Sealing Screws Work

When installed, screws with rubber seals provide a dual function: the threaded engagement locks the fastener in place, while the embedded O-ring creates an airtight and fluid-tight seal around the head. This makes them indispensable in sectors such as aerospace, automotive and medical, where preventing fluid leaks or dust ingress is paramount.

For example, in an automotive engine control unit, a screw with seal can be used to protect sensitive electronics from oil or coolant seepage. Meanwhile, in medical device enclosures, an o-ring screw helps keep delicate instruments shielded from moisture and corrosion.

Materials Sealing Screws Are Made From

Accus range of screws with rubber seals are manufactured from high-grade stainless steel A2, well known for its corrosion resistance and tensile strength. This makes them suitable for a variety of challenging environments, including medical and chemical processing applications.

Depending on your sealing requirements or exposure to specific chemicals, you can choose from various O-ring materials such as buna (nitrile) for general-purpose sealing, fluoro silicone or silicone for wide temperature ranges and viton for excellent chemical resistance.

Size and Type Sealing Screws Available

Accu proudly stocks a huge range of Zago sealing screws spanning both metric and imperial standards. Metric thread sizes run from M2 (2mm) to M12 (12mm), with lengths available from 4mm to 60mm. Imperial sizes begin at #2-56 UNC and go up to 1/4"-20 UNC, with lengths ranging from 3/16" to 1 3/4".

Head styles include countersunk, cap head, pan head and button head, while drive types encompass hex socket, Torx, Phillips and slotted, ensuring there’s a sealing screw configuration for nearly every project application.

For enhanced performance, we also offer various finishing options, such as custom manufacturing or a thread-locking patch application known as AccuLock. If you need to ensure secure fastening without thread loosening, consider pairing these with AccuLock which will provide resistance against loosening.

FAQs

Q: What do you use to seal screws?

A: Sealing screws use an integrated rubber O-ring that compresses tightly between the screw head and the mating surface. This O-ring is typically made from materials like buna, silicone or viton, offering different levels of chemical and temperature resistance.

Q: What is the difference between viton, silicone and buna sealing screw o-rings?

A: Viton offers outstanding chemical resistance and high-temperature performance, making it ideal for harsh environments. Silicone performs well in extreme temperature ranges but is not as resistant to certain chemicals. Buna (or nitrile) balances durability with general-purpose chemical resistance, making it a popular and cost-effective choice for many applications.

Bespoke Sealing Screws With O-Rings Manufacture.

High precision, bespoke manufacture of Sealing Screws With O-Rings to customer specification. State of the art facilities specialising in both small batch prototyping and large scale manufacture.