Caps, Plugs & Corks
These are the most popular industrial masking caps, plugs and corks products. Silicone rubber masking with a high temperature rating of 600°F is the industry standard for powder coating, ecoating and anodizing, while EPDM rubber at a 350°F max temp is often the option for painting, blasting and plating. Wood corks are ideal for wet spray painting.
Series: STP
Silicone Tapered Plugs
Save time and money by masking quickly and at low-cost with silicone tapered rubber plugs in powder coating, anodizing, electroplating and ecoating processes. Reusable silicone plugs rated to 600°F cover hole diameters from 0.062" to 4.75".
Series: STP-H
Silicone Tapered Plugs with Handle
The added length allows for fingers large and small to quickly grasp the handle and insert/remove these smaller plugs. The handle also allows a quick twist to push plugs in a bit further and with more friction, helping to avoid blowouts in components that are heated and trap air beneath the plugs.
Series: SC
Silicone Straight Wall Caps
Engineered to withstand temperatures up to 600°F (315°C), these caps are highly durable, chemical resistant and 100% reusable. Over 85 standard sizes in stock for masking studs, threaded bolts, and tube ends during finishing operations.
Series: SPP
Silicone Pull Plugs
Pull plugs make quick work of thru-holes with a single plug to mask paint and other coatings. Withstands up to 600°F. Masks both threaded and non-threaded through holes. Reusable high-grade silicone rubber.
Series: VTMP
Silicone First Thread Masking Plugs with Handle
Masking plugs for SAE, UNC or metric threads where the first thread must also be masked. Ideal for powder coating, anodizing or other metal finishing. Rated to 600°F, fully cured silicone, reusable.
Series: SFPP
Silicone Flanged Pull Plugs
Designed to keep the top or first thread clean during industrial finishing — when no powder, paint or anodizing is allowed. Eliminates rework by masking weld nuts and top threads in one step. 40-45 durometer Shore A silicone. These indispensable masking plugs reduce costs by speeding up the process of masking 82° and 90° countersinks. To use, insert 'tail' into thru-hole, then pull plug into place with flange resting on opposite side for first thread protection.
Series: SCE
Silicone Expandable Caps
Single caps that mask several different thread sizes, eliminating the need for multiple individual sizes while saving storage space. Dual-rib internal design enables expansion across multiple sizes. Rated to 600°F. For example, to mask a 1/4-20 thread and a 5/16-18 thread, two different caps would be required (our part numbers SC234 and SC281). But with just one SCE-236-354, not only can both of those sizes be masked with that one plug, but a 3/8-16 thread can be masked with it too.
Series: SFP
Silicone Flangeless Plugs
Especially well suited for threaded holes — can be twisted into blind, threaded holes tightly with the ribs holding the plug more securely. Color-coded for easy identification. Rated to 600°F. Compared to standard tapered plugs, they can be twisted into blind, threaded holes tightly with the ribs holding the plug more securely. This can be extremely usefu when a strong seal is required to prevent leaks in anodizing or blow-outs in powder coating or ecoating. The shallow taper and narrow handle allow for complete masking while reducing shadowing during coating. SFP's are easy to insert and remove and are re-usable.
Series: HTP
Silicone Hollow Tapered Plugs
Engineered to provide a superior seal while remaining a cost-effective alternative to standard solid plugs. 20-30% cost savings compared to solid versions. More flexible for easier insertion, with walls that collapse slightly for irregular holes.
Series: VFC
Silicone Flange Caps
Reusable masking caps designed to protect studs, bolts, and surrounding circular areas during high-heat finishing processes. Ideal for masking studs or bolts and a circular area around them, typically for grounding area protection. Our silicone flange caps eliminate the need for secondary washers by masking the circular area around the bolt, saving labor time in powder coating and e-coating lines. Alternatively can be used as a plug: The area around a hole can then be masked by the flange. They have also been used successfully as an insulation for wire harnesses (by cutting off the rounded end).
Series: VMFP
Silicone Multi-Flange Plugs
Multi-Flange Plugs (VMFP's) are a great option when the priority is being able to mask as many different holes sizes with a small inventory of plugs. Perfect for small powder coaters and job shops, these plugs allow for masking holes from 0.109" up to 0.709" with just three different plug sizes. With regular tapered plugs, that would take up to 15 plugs or more. Multi-flange plugs have a progressively larger tapered flanges on them, so they can be used for masking chamfers in threaded holes, or for the first thread in threaded holes that tapered plugs can't.
Series: TFP
Silicone Tapered Flange Plugs
Silicone tapered flange plugs are recommended for powder coating, e-coating, anodizing and plating, establishing concentric masks around holes for metal finishing applications. These silicone masking aids are ideal for establishing grounding surfaces. They have also been used successfully to insulate wiring and wire harnesses (by clipping the end off the plug and feeding the wires through it).
Series: ETP
EPDM Tapered Plugs
EPDM tapered plugs are a great all-purpose solution to wet spray paint, plating and anodizing masking requirements of blind or through holes where carbon can be introduced to tanks safely. Rated to 350°F.
Series: EC
EPDM Straight Wall Caps
EPDM rubber caps are often used for masking parts in anodizing, painting operations, plating tanks and similar thermal applications up to 350°F. Great chemical resistance, reusable, moderate blasting resistance.
Series: EPP
EPDM Pull Plugs
EPDM pull plugs mask a through-hole in its entirety with a single plug by placing the narrow end through and pulling the large diameter end through. Rated to 350°F with excellent chemical resistance. Reusable.
Series: C-REG
Wood Corks
Tapered wood corks designed as a rugged, inexpensive alternative to silicone or EPDM when masking blind holes in high-volume painting operations. Specifically engineered for wet spray paint masking, these corks withstand no-bake air drying and low-bake oven cycles up to 300°F (149°C). • Precision Fit: Naturally tapered design ensures a tight seal. • Heat Resistant: Safe for use in wet spray environments. • Eco-Friendly & Reusable: A sustainable, biodegradable masking choice. Viadon's wood corks are standard grade quality to balances low-cost with functionality. Corks are in stock and usually ship same day. Premium grade also avaiable (lead time and minimums apply); call or email for details. Rated for temperatures up to 300°F. Reusable.
Need a Custom Size or Shape?
We provide custom parts to your exact specifications with fast turnaround.
- Low-cost tooling, 7-10 day lead time
- Large inventory of in-stock tools
- Rectangles, squares, circles, and custom shapes
- Precision slit-to-width available
- Free samples on most products
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