Mateusz

☎ 67 350 53 69
📱 535 546 903
mateusz@hydron.com.pl

Krzysztof

☎ 67 350 53 69
📱 574 407 377
krzysztof@hydron.com.pl

Rafał

☎ 67 350 53 69
📱 575 402 207
rafal@hydron.com.pl

Marek

☎ 67 350 53 69
📱 535 144 571
marek@hydron.com.pl

Łukasz

☎ 67 350 53 69
📱 530 565 162
lukasz@hydron.com.pl

Łukasz

☎ 67 350 53 69
📱 575 887 568
lukasz.kapeja@hydron.com.pl

Roman

☎ 67 350 53 69
📱 575 887 703
roman@hydron.com.pl

Marcin

☎ 67 350 53 69
📱 530 454 305
marcin@hydron.com.pl

Tapered plug NPT 3/8"

Go to Product feedback

€1.70

Shipping costs are not included in the price.

Quantity

pcs

Availability:

In stock

Darmowa przesyłka od 100 zł

Do darmowej dostawy brakuje Ci jedynie 100 zł

Masz darmową dostawę ✓

Manufacturer: HYDRON hydraulika siłowa (go to products)

Shipping time: 24 hours

Shipping

from €3.62 - GLS Courier (Poland)

Our top pick :) Our warehouse packs orders until 3:00 PM, and GLS picks them up at 5:00 PM. It’s our customers’ most popular choice and the courier that works best for us.

Ask about the product

Tapered plug 3/8" NPT 4N-06

Tapered plug 3/8" NPT 4N-06 is a metal threaded plug designed for closing holes with an internal tapered NPT thread. The product has a 3/8"-18 NPT external pipe thread, used in power hydraulics, pneumatics, and industrial systems. The tapered construction allows for a tight connection through the cooperation of the threads and the application of an appropriate sealant.

The plug with the designation 4N-06 is used for plugging unused connections, technological holes, and ports in compatible installation components. It can be used during assembly, modernization, and servicing of equipment, provided that the thread and the permissible operating parameters of the connection are consistent.

Note: Illustrative photo. Due to differences in the technological process, the fitting may be delivered in a different visual version than presented in the photograph. Differences may concern the external appearance of the element.

Technical parameters of the tapered plug 3/8" NPT

Product type: tapered plug, threaded plug.
Product designation: 4N-06.
Nominal thread size: 3/8".
Full thread designation: 3/8"-18 NPT.
Thread type: external, tapered.
Thread system: NPT – National Pipe Taper.
Number of turns: 18 per inch (18 TPI).
Thread pitch: about 1.411 mm.
Thread profile angle: 60°.
Thread taper: 1:16 relative to diameter.
Sealing method: on the mating thread surfaces, using an appropriate sealant.
Purpose: closing compatible holes with an NPT internal thread.
Application areas: power hydraulics, pneumatics, and industrial installations.

Application of the NPT 3/8" plug in power hydraulics

The NPT 3/8" 4N-06 plug is used for closing threaded holes in components using the American NPT tapered thread system. The plug can be used in compatible bodies of manifolds, valves, pumps, and other hydraulic system elements.

The product is also used during maintenance and service work, when it is necessary to close an unused connection or protect a selected port. Before installation, confirm the compatibility of the thread system, the working medium, and the required operating parameters.

Tapered thread 3/8"-18 NPT – construction and dimensions

The 3/8"-18 NPT designation specifies an American pipe tapered thread with a nominal size of 3/8" and 18 turns per inch. The profile angle is 60°, while the thread taper is defined by a 1:16 ratio relative to the diameter. This means that the thread diameter changes along its axis.

The 3/8" nominal size does not correspond directly to the external diameter of the thread measured with a caliper. For identification, use NPT dimension tables and consider the location where the measurement was taken on the tapered surface.

Sealing of the NPT 3/8" tapered plug

NPT connections use mating tapered threads, which achieve increasing pressure during tightening. In typical applications, an appropriate pipe thread sealant is used to ensure the required tightness, selected for the working medium and installation parameters.

This can be, for example, a properly selected anaerobic sealant or PTFE tape, provided its use is permitted in the given system. Follow the sealant manufacturer's recommendations and prevent excess sealant from entering the installation.

Differences between NPT 3/8" and BSPT 3/8" threads

NPT and BSPT are two different tapered pipe thread systems. NPT thread has a 60° profile angle, while BSPT uses a 55° profile. For the 3/8" size, the number of turns also differs: NPT has 18 TPI, and BSPT 19 TPI.

Despite similar nominal designations, an NPT 3/8" plug should not be replaced with a BSPT 3/8" plug. Incorrect selection can lead to thread damage, assembly difficulties, and connection leaks.

How to recognize an NPT 3/8" thread?

A caliper, an inch thread pitch gauge, and an appropriate thread gauge can be used to identify an NPT thread. The basis is to confirm the tapered nature of the thread, its dimensions, and a pitch of 18 turns per inch.

In the case of tapered threads, the diameter measurement result depends on where the caliper jaws are applied. Therefore, for unambiguous identification, it is recommended to compare results with technical documentation and an appropriate gauge.

Designation 4N-06 – plug identification

The symbol 4N-06 is a catalog designation used for a plug with a 3/8" NPT external thread. This designation facilitates product searching during the selection of fittings, plugs, and ordering replacement parts.

When comparing products from different suppliers, check thread compatibility, construction, and operating parameters. Similar catalog symbols do not always mean identical material or surface execution.

Possible differences in plug appearance

The product photo is for illustrative purposes. Due to differences in the technological process, the 3/8" NPT 4N-06 tapered plug may be delivered in a visual version different from the photograph posted in the store.

When identifying the product, one should primarily be guided by the 4N-06 designation, the type and size of the thread, and the technical parameters. External appearance should not be the only criterion for selecting a hydraulic plug.

Selection and assembly of the NPT 3/8" tapered plug

Before assembly, ensure the hole has a compatible 3/8" NPT internal thread. Thread condition, sealing type, and permissible operating parameters must also be checked. Do not install the plug in a connection with damaged or incompatible threads.

The installation should be turned off and safely depressurized. Then, the threaded surfaces should be cleaned, the appropriate sealant applied, and the plug tightened according to the connection requirements. Excessive tightening of the tapered thread can damage the device body. After assembly, a leak check under safe conditions is necessary.

Technical specification

Parameter	Value
Product name	Tapered plug 3/8" NPT
Designation	4N-06
Nominal thread size	3/8"
Full thread notation	3/8"-18 NPT
Thread type	External, tapered
Number of turns	18 TPI
Profile angle	60°
Taper	1:16 relative to diameter
Sealing	On the thread, with appropriate sealant
Application	Hydraulics, pneumatics, industrial installations

Frequently Asked Questions (FAQ)

What thread does the 4N-06 plug have?

The 4N-06 plug has a 3/8"-18 NPT external tapered thread with a 60° profile angle and 18 turns per inch.

What is the 3/8" NPT tapered plug used for?

It is used for plugging compatible threaded holes in hydraulic, pneumatic, and industrial installations.

Does the NPT 3/8" plug require sealant?

In typical NPT connections, a sealant designed for pipe threads is used, appropriate for the medium, pressure, and operating temperature of the system.

Is NPT 3/8" thread the same as BSPT 3/8"?

No. NPT has a 60° profile angle and 18 turns per inch, while BSPT has a 55° angle and 19 turns per inch. The threads are not intended for direct interchangeable use.

What does the symbol 4N-06 mean?

It is a catalog designation of a plug with a 3/8" NPT external thread, helpful during product identification and ordering.

Can the delivered plug look different than in the photo?

Yes. The photo is for illustrative purposes. Due to differences in the technological process, the fitting may be delivered in a different visual version than presented in the photograph.