Understanding Your Choices in Fastener Seals

One of the most basic, yet critical, decisions when putting together almost any piece of hardware is your choice of fastener seals.  At their most basic, fastener seals are simply a piece of rubber surrounded by a metal ring that acts as support.  Used properly, they eliminate clearance gaps between attached components, while also preventing leaks in many static applications.

Dichtomatik specializes in seals and sealing products – we’re among the world’s most trusted sources for sealing solutions. We carry a vast array of bonded seals, thread seals, and more – along with having the capability of producing custom seals built to order.  Our bonded seals are most typically made of NBR rubber, surrounded by zinc-plated carbon steel.  However, they can be manufactured with a variety of materials.

Any fastener seal order starts by knowing what type of seal your application calls for.  These are some of the most common types we provide, and some of their usage scenarios.

Choosing the Right Fastener Seal for Your Job

  1. Bonded seals 

A bonded seal is the most basic form of fastener seal and is very similar to a standard washer.  Both the outer metal ring and the inner rubber ring are smooth, and they work well with a wide variety of general fittings.

  1. DC Fastener Seals

Fastener seals are quite similar to bonded seals, but with one important distinction. The inner edge of the metal ring is ridged, leaving small gaps for the rubber ring to compress into. This gives them a tighter seal when used beneath the head and along the base of the bolt while maintaining accuracy in the seal placement. They can be sized to accommodate virtually any standard fastener.

  1. DCCL Thread Seals

DCCL thread seals are different from other variations by having a triangular seal in the middle, rather than a simple round ring.  This allows the thread seal to conform more precisely to threaded bolts and create a better seal against fluid leakage.  Yet, they don’t require special equipment to utilize, making it easier to work on the parts they seal.


Whatever your needs, Dichtomatik US has both the stock and the expertise necessary to meet them.  If your project calls for fastener seals, contact us to find the perfect fit.

Download our size listings.