AC&M Cup Seals -- In a Class of Their Own

AC&M Cup Seals -- In a Class of Their Own

Posted by Steve Diebold



AC&M Cup Seals are unique metal 2-piece devices that have strong 360-degree multi-point locking rings with hard sharp teeth around the entire inside circumferences. Once the two pieces of a Cup Seal are locked, they can only be opened by destroying the seal with tools. Any attempts to open a Cup Seal will be visible. The system is so effective that it is used on some of the most sensitive and high value closures known.

They are available with galvanized steel, or copper and brass bodies, providing durability against physical damage, extreme temperatures, and corrosion. Once people see this seal, they immediately know it is a formidable deterrent to attempts at opening and it will stay locked and in good condition for a long time.



Cup seals are used two ways. One is as a wire seal which uses a twisted wire of any length required that can be attached through an opening of 1mm or greater to provide a highly effective tamper seal.

Wire is put through 2 holes in the bottom of the seal and tied together inside the housing before the seal is locked -- for an extremely high level of security.

Some popular uses of cup seals with wire include hazardous material containers, nuclear materials in storage and transport, precious metals and various chemical, food processing and petrochemical refinery systems meters and measuring equipment. Valve and switch lockouts are a common application in processing systems but there are numerous other uses in those facilities.

Several key governmental and international nuclear regulatory and inspection groups choose AC&M Cup Seal for both their effective performance and the exceptional service provided by our company.


This function is a unique system where a single hole allows the bottom of the seal to be attached to a device with a screw or bolt. Then the top of the seal is locking into place, preventing the screw from being removed without destroying the seal (cover the protection of the screw guards against unauthorized opening of all kinds of devices.). Because it is a metal seal, it cannot be opened and then glued or otherwise appear closed.

AC&M offers a range of standard hole sizes to fit both inch and metric size fasteners with a range of common head and screw diameters.

You can find cup seals for screws and bolts protecting things like calibrated test equipment, racing engines after passing qualifying inspections, metering devices, electronics, servers, controls, switching equipment and much more.


Cup Seals are available with stamping of letters, serial numbers and other marking as may be required to make every seal unique and enable monitoring and tracking.

The seals can be supplied in bulk to save costs or packed carefully into small boxes in numerical order to carefully apply your cup seals under a highly controlled protocol. The wide selection of hole size options and shape/location options allow the user to fit the seals to their needs.

Some who use Cup Seals add internal markings or “traps” that are put inside the seal before locking. A “trap” is something that will be altered or would change appearance or position if the seal were opened. Once that occurs there is both the evidence of the damaged seal and the internal evidence of the trap. It can be made into the ultimate in tamper detection or simply used as the extremely highly effective it is right out of the box.


If you need the most effective and reliable tamper evident seal available, then check out the Cup Seal from AC&M. There are hundreds of security seals to choose from, but the best of the best is made our factory in Plainview, NY and has been made there for decades. Our 110 years of seal manufacturing experience demonstrates the commitment and trust we share with our thousands of loyal customers. Whether they user our most basic plastic seal or the high performing Cup Seal or any of over 100 seal types, we are the source trusted to delivery, the best seals with superior service and fast delivery.

Contact AC&M for more information or samples of the Cup Seal to evaluate this unique seal for your application. Experts are available to talk with you by phone or online chat during business hours in the EDT time zone, or you can find details and place an order 24/7 at our web site.