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Square Silicone Plugs

Square Silicone Plugs

Square silicone plugs are designed to mask both square and round holes. They are suitable for low- and high-temperature applications and can be reused multiple times.

Processes: powder coating, e-coating, anodising, plating.
Maximum temperature: 480°F (250°C)
Hardness (shore): 50A

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  • Global delivery in approx. 10-14 days
  • Custom sizes available on request — quote within 24h
  • Volume pricing available on request
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Select Size

Part No. D1 (mm) D2 (mm) L1 (mm) L2 (mm) L3 (mm) Qty/Pack Color Price Order Qty Add to Cart
SQSP-001 9.50 12.70 9.50 12.70 15.90 100 Blue $48.16
SQSP-002 12.70 15.90 12.70 15.90 19.10 100 Green $92.53
SQSP-003 15.90 19.10 15.90 19.10 19.10 100 Black $135.18
SQSP-004 22.20 25.40 22.20 25.40 25.40 50 Red $164.97

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Frequently Asked Questions About Silicone Plugs

How do I select the correct silicone plug size?

The general rule of thumb is to select a plug that is 5–10% larger than the hole diameter to ensure a secure interference fit that seals tightly and stays in place during the curing cycle. For tapered plugs, choose a size where the hole diameter falls within the plug's tapered range — ideally near the middle — so the plug seats firmly without being forced in or falling through.

What is the maximum temperature rating for silicone masking plugs?

All of our silicone masking plugs are manufactured from high-grade silicone rubber rated for continuous exposure up to 250°C (482°F). This makes them fully compatible with the curing cycles of powder coating, e-coating, anodizing, and most industrial baking processes without melting, hardening, or degrading.

Are silicone plugs reusable, and how many cycles can they withstand?

Yes, silicone masking plugs are highly reusable, which makes them a cost-effective solution for series production. Depending on the curing temperature, duration, and the specific coating process, customers typically achieve 10 to 20 reuse cycles. After curing, accumulated powder coating can usually be easily flaked or rolled off the flexible silicone surface. Avoid using harsh chemical strippers, as they can degrade the silicone over time.

What are the benefits of pull plugs?

Pull plugs feature a protruding handle or 'tail' that is pulled through the hole from the other side. As the plug is drawn into place, the silicone body contracts and creates a very secure interference fit against the hole wall — providing an exceptionally tight seal. This also makes removal fast and ergonomic: the handle can be gripped and pulled out cleanly without tools, even when wearing gloves, making them ideal for high-volume production environments.

Does MaskingSupply provide custom moulded silicone plugs?

Yes. If our standard range does not fit your specific hole geometry, thread profile, or production requirement, we can manufacture custom moulded silicone plugs to your exact specifications. Custom plugs are ideal for non-standard diameters, complex geometries, or high-volume applications where a perfect fit is critical. Quotations are typically provided within 24 hours, and samples are available within 2 to 3 weeks. Contact us to discuss your requirements.

What are threaded plugs and plugs with ridges used for?

Threaded silicone plugs are designed to screw directly into threaded holes, providing a highly secure fit that protects the thread from powder and liquid ingress during coating and finishing processes. Plugs with ridges or fins work on the same principle in threaded holes: the ridges compress against the thread profile and create multiple sealing points for a highly secure seal.