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Magnetic Expansion Sealing Plugs

Magnetic expansion sealing plug: a magnetic core lets the plug be handled and located with a magnet, and expansion locks it in the bore.

Key specifications

MaterialBrass / Stainless Steel
Installationthreaded in with radial or face sealing
StandardGB/T 197, GB/T 3452.1
Typical substrateprocess and test ports
Key inspectionspressure hold, seal hardness

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Product overviewOverview

Process holes are often not precision-machined, so roundness and roughness vary. Expansion plugs seal by deforming against the bore wall rather than by thread compression, so bore finish and roundness control the seal. The magnetic core is there for handling and for swarf capture in service, not for sealing, and it should not be confused with a magnetic drain plug function.

Material: Brass / Stainless Steel. It is threaded in, sealing either radially or on the face.

Key featuresFeatures

Seal comes from bore deformation; the magnet is for handling.
Integrated O-ring or rubber sleeve seals on installation without sealant.
Magnetic versions capture ferrous debris and keep circuits clean.
Brass, stainless or aluminium bodies for different media.

Typical applicationsApplications

Engine and gearbox test ports
EV drive cooling cavities
Pneumatic component bodies

Selection notesSelection

Follow the specified tightening torque: over-tightening is the main cause of sleeve failure.

Frequently asked questionsFAQ

Does the magnetic core collect wear debris?

It can hold ferrous particles near the plug, which is useful in a gearbox or sump but is not its primary purpose. Sealing still depends on the expansion element against the bore.

What matters during installation of the Magnetic Expansion Sealing Plugs?

Thread it in, sealing either radially or on the face. Seal comes from bore deformation; the magnet is for handling.

Specifications

Material	Brass / Stainless Steel
Sealing	O-ring seal
Standard	GB/T 197, GB/T 3452.1
Head style	pan head
Installation	threaded in with radial or face sealing
Typical substrate	process and test ports
Key inspections	pressure hold, seal hardness

Manufacturing and inspection

Sleeve hardness and compression set sampled; O-rings to GB/T 3452.1.Alternative materials and finishes can be quoted side by side during sampling, so cost and corrosion resistance can be traded off explicitly.