Brass Plugs & Caps

When thread leaks lead to pressure drops or media contamination, plug and cap fittings must do more than block a port. Our Brass Plugs & Caps provide thread-match precision, sealing compatibility, and material-grade control to support regulated flowhttps://en.wikipedia.org/wiki/O-ring systems across multiple configurations.

Product Type

Hex Head Plug, Square Head Plug, Round Head Cap, Flanged Cap, Countersunk Plug

Thread Size

#4-40 to 2″ (Metric: M3 to M50)

Thread Type

NPT, BSPT, BSPP, Metric (Internal/External)

Thread Tolerance

Class 2B (Internal), Class 2A (External) – Custom to ISO 228/ASME B1.1

Material Grade

C36000 (Free-Cutting Brass), CW617N (EN), C37700 (Forging Grade)

Product Description

We support wide thread types, sealing grooves, and size options to match line specifications without adding adapters. Each unit is machined from C36000, CW617N, or C37700 brass with optional O-ring grooves, conical seats, or coating finishes based on your system load and media.

Pressure Rating

150 PSI – 1000 PSI (10.3 – 69 bar) (size-dependent)

Temperature Range

-65°F to 400°F (-54°C to 204°C)

Head Type/Style

Hex, Square, Round, Flanged, Knurled, Countersunk

Overall Length/Height

0.2″ – 2.5″ (custom lengths for deep sealing)

Hex/Square Size

0.25″ – 1.5″ (e.g., 1/2″ NPT Plug: 7/8″ Hex)

Sealant/Sealing Feature

NPT (Tapered Self-Sealing), O-Ring Groove, PTFE Tape Seat, Conical Seat

Internal/External Config.

Internal (Female) Threaded Plug / External (Male) Threaded Cap

Finish/Coating

Plain Brass, Electroless Nickel (ENP), Chrome, Powder-Coated (Custom Colors)

Standards Compliance

ASME B1.20.1, ISO 228, DIN 7604, ANSI B16.11, WRAS (Water Approved)

Weight

0.01 lb – 1.2 lb (size/material-dependent)

Wall Thickness

0.05″ – 0.3″ (heavy-duty for high-pressure/vibration)

Technical Advantages

Unlike standard hardware options, our brass plugs and caps allow controlled thread tolerance, wall thickness, and sealing integration. We support thread sizes from #4-40 to 2 inch or M3 to M50, with internal or external formats and sealing grooves based on torque rating.

Heavy wall thickness options from 0.05 inch to 0.3 inch prevent thread distortion under high tightening force or repeated removal. Optional coatings like electroless nickel or powder finish improve surface wear resistance in exposed or corrosive environments.

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Industry Applications

Hydraulic Manifolds

Threaded plugs in Class 2A/2B tolerance prevent leakage and galling under pulsating pressure in mobile and industrial fluid systems.

Gas Regulators and Valves

BSPP or NPT external-thread caps with conical sealing prevent gas escape during long storage or shipping of assemblies.

Water Filtration Units

Corrosion-resistant round or hex plugs with WRAS-compliant materials maintain hygiene and resist dezincification in potable water lines.

Pneumatic Equipment Frames

Caps with knurled grip support frequent removal during maintenance, while PTFE tape grooves ensure airtight seals.

Sensor Port Closures

Countersunk brass plugs seal unused test or sensor ports with flush surfaces to avoid protrusions in compact systems.

Control Panel Assemblies

Chrome-plated hex-head caps offer electrical insulation and thread protection for unused terminal ports in enclosures.

Configurable Fit with System-Driven Utility

Volume buyers seek thread compatibility, corrosion resistance, and torque control without changing their mating components. Our plugs and caps solve these pain points using thread-matching flexibility, finish options, and pressure-specific wall profiles.
 
We allow size-specific head styles like square, flanged, or countersunk to reduce profile height or simplify tool access. This ensures faster integration into product lines without needing thread adapters or internal redesigns. 

Having Doubts? Our FAQ

Check all our Frequently Asked Question

Can we get plugs or caps that match existing thread tolerances on our legacy units?

Yes, we support Class 2A/2B as standard but also machine threads to ISO 228 or DIN 7604 when legacy fitment is required. This ensures no over-tightening or under-seating during assembly. We also adjust pitch diameter ranges based on your mating part’s measured data.

Is it possible to adjust the head style to fit tool clearance limits or reduce outer profile?

We offer hex, square, flanged, and low-profile countersunk styles with size-specific height options. This supports tight panel layouts or flush sealing requirements without post-machining. Tool clearance, hand access, and surrounding components are factored before we confirm the design.

Can surface finish be changed depending on media or exposure conditions?

Yes, we provide plain brass, electroless nickel, chrome, or powder-coated surfaces depending on media contact, temperature, or visual needs. This supports use in corrosive, high-humidity, or visible consumer-facing zones. We recommend finish based on your fluid or installation environment.

Will you support mixed thread types in a single shipment for multiple equipment variants?

We can ship plug and cap variants with BSP, NPT, and metric threads within the same batch. This suits projects involving multi-region systems or transition units. Each unit is thread-verified before dispatch to avoid mismatches during assembly.

How do you handle requests for custom sealing features like O-ring grooves or conical seats?

We machine sealing options such as O-ring grooves, conical seats, or flat-face stops based on your mating component geometry. This allows leak-free function even under vibration or pressure cycling. Our team evaluates thread depth and torque load to propose a matching seal feature.

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LOCATIONS

Global Sales Office

818, Preakness lane, Coppell, Texas, USA – 75019

Registered Office

10-A, First Floor, V.V Complex, Prakash Nagar, Thiruverumbur, Trichy-620013, Tamil Nadu, India.

Operations Office

9/1, Poonthottam Nagar, Ramanandha Nagar, Saravanampatti, Coimbatore-641035, Tamil Nadu, India. ㅤ

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GENERAL ENQUIRIES

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Brass Plugs & Caps

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Brass Plugs & Caps

Need reliable Machining for your next project? Get in touch with us today, and we’ll help you find exactly what you need!

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