Reusable protection for threads and connectors during painting, powder coating and baking processes.
Why use silicone caps?
Silicone caps are reusable temporary protectors placed over welding elements before finishing processes, particularly painting, powder coating, baking and heat treatment. They prevent paint, powder or residue from obstructing or damaging critical mechanical areas such as external threads, internal threaded holes and Faston-type electrical connectors.
Once the finishing process is complete, the caps are removed and can be reused many times.
Technical properties of the material
| Property | Value / specification |
|---|---|
| Material | High-quality vulcanised silicone |
| Maximum continuous temperature | ≤ 210 °C |
| Peak temperature (short duration) | ≤ 300 °C |
| Reusable | Yes (hundreds of cycles) |
| Chemical resistance | Good resistance to paints, solvents and oils |
| Elasticity | High (adapts to different tolerances) |
Note: They must not be exposed to temperatures above 300 °C or to direct flames, as this would degrade the silicone.
Types of silicone caps
The BEARFIX® catalogue classifies the caps into four main models:
3.1. Cap for threaded studs (PT type) and unthreaded studs (UT type)
Shape: Closed cylindrical cap.
Function: Fully covers the external thread and the end of the stud.
Available diameters: From M3 to M10 (on request).
Typical use: Studs that will protrude from the insulation or receive nuts after painting.
3.2. Cap for internally threaded studs (IT type)
Shape: Small solid plug inserted into the threaded hole.
Function: Seals the hole to prevent paint from entering the internal thread.
Available diameters: For M3, M4, M5 and M6 threads (on request).
Typical use: Hollow studs or internally threaded bushes.
3.3. Cap for earth connector (single Faston)
Shape: Hood that fits around the 6.3 mm female Faston connector.
Function: Protects the internal metal tabs.
Typical use: Earth connections in vehicle bodies, household appliances or electrical cabinets.
3.4. Cap for double earth connector (double Faston)
Shape: Two cavities joined in a single piece.
Function: Simultaneously protects two adjacent Faston connectors.
Typical use: Earth branches or dual electrical connections.
Important note: The exact dimensions of these four cap types are available on request and can be manufactured to suit customer requirements.
Summary table of cap types
| Type | Element to protect | Typical application |
|---|---|---|
| PT / UT | Threaded / unthreaded stud | Protect the external thread before painting |
| IT | Internally threaded stud | Seal the threaded hole |
| Single Faston | Earth connector (6.3 mm) | Prevent paint from entering electrical connectors |
| Double Faston | Double earth connector | Simultaneous protection of two connectors |
Applications by sector
- HVAC and air conditioning: Protect threaded studs in ventilation ducts.
- Household appliances: Cover earth Faston connectors in washing machines, tumble dryers and refrigerators.
- Automotive: Protect internal threads in frames and brackets.
- Metal construction: Prevent paint from entering threaded holes in structures.
Purchasing recommendations
We recommend requesting samples before placing large-volume orders to verify that the caps fit correctly. It is also advisable to maintain rotating stock at least 10% to 20% higher than the number of studs used per batch. To extend their service life, store the caps in a dry place away from direct sunlight. Finally, replace caps when they harden or crack, which generally occurs after several hundred use cycles.