Mardatt M-97 3/4" NPT Carbon Steel Pipe Plugs, 10-Piece Set

For closing an unused threaded port on an engine block, oil tank or drain pipe, the Mardatt M-97 set provides ten matching 3/4" NPT plugs. Each plug has male threads and a hex-drive socket for installation. The carbon steel construction and black finish suit practical fitting and maintenance tasks where a threaded closure is needed.

The essentials

This set includes ten 3/4" NPT pipe plugs, giving you matching pieces for several ports or spares for future maintenance. The male NPT thread is designed for a corresponding 3/4" NPT connection, so check the fitting’s thread type and size before installation. NPT is a tapered pipe thread standard, matching the connection helps create the intended threaded fit.

Carbon steel gives each plug a solid metal construction, while a rust-resistant oil is applied to the surface. The black finish keeps the plugs visually consistent with dark fittings and components. Each measures 1.04" L x 0.62" H, a compact format for threaded ports where a plug is preferable to a welded closure. The hex-drive socket provides a practical way to tighten or remove the plug with a suitable tool.

Practical tips

Before fitting a plug, make sure the port is clean and that the threads match. Apply thread sealant, such as tape or paste, to the male thread to aid sealing, then tighten the plug with a wrench or suitable hex-drive tool. Applying sealant to the male thread only follows the product guidance and keeps the fitting process straightforward. For removal, use the drive feature to loosen the plug when access and the surrounding assembly allow.

A threaded plug offers a removable alternative to welding when a compatible port needs to be closed. That makes this set useful for maintenance work where access to the connection may be needed again, rather than a permanent closure. Its standardised size also makes it easier to select when replacing a matching 3/4" NPT plug.

Everyday use

These plugs are intended to help close compatible openings and prevent leakage of air, gases, oil or other fluids in applications such as engine blocks, oil tanks and drain pipes. For example, when servicing an assembly with an unused 3/4" NPT port, fit a plug into the matching threaded opening and use sealant on the male thread to aid the seal. The Allen-style drive is useful where a socket-head plug is preferred, and the set of ten supports jobs involving multiple ports or repeat maintenance.

Choose these over a permanent welded closure when you need a threaded plug that can be removed for later access. The important selection point is the connection itself: the port must be a matching 3/4" NPT thread. Once matched, the carbon steel plugs provide a straightforward threaded option for routine industrial and equipment maintenance.

Buying verdict

The Mardatt M-97 set suits repair and maintenance tasks that call for several compact, removable 3/4" NPT closures. Its ten-piece count, male tapered threads and hex-drive design make it a practical choice for matching ports on equipment such as engine blocks, oil tanks and drain pipes. Keep the thread size and NPT type aligned with the fitting, and use sealant on the male thread when installing to aid sealing.