Square oil plug screw

Cold heading process is one of the new processes for pressure machining of less or no cutting
metal. It is a processing method that utilizes the plastic deformation of metal under the action of
external forces, and with the aid of molds, redistributes and transfers the volume of metal to form
the required parts or blanks. The cold heading process is most suitable for producing standard
fasteners such as bolts, screws, nuts, rivets, and pins.etc

Description of a Square Oil Plug Screw

A square oil plug screw is a threaded fastener designed to seal oil or fluid ports in mechanical systems, such as engines, gearboxes, and hydraulic units. Its defining feature is a square-shaped head, which allows for easy installation and removal using a standard wrench or square-drive tool.

Key Features & Design Elements

1. Head Design

• Square head (typically 4-sided) for wrench engagement.

• Some versions have a flanged base to improve sealing and distribute pressure.

• Low-profile design to prevent snagging in tight spaces.

2. Thread Type

• Tapered threads (NPT – National Pipe Taper): Creates a tight seal when screwed in, commonly used in fluid systems.

• Straight threads (NPS/BSPP): Requires a sealing washer or O-ring to prevent leaks.

• Metric or SAE (Imperial) thread standards, depending on application.

3. Sealing Mechanism

• Integrated O-ring or rubber gasket (for reusable, leak-proof sealing).

• Copper or aluminum crush washer (single-use, deforms to create a seal).

• Tapered threads (self-sealing in NPT plugs).

• Some plugs have magnetic tips to capture metal debris in oil systems.

Primary Applications

• Engine oil drain plugs (cars, motorcycles, heavy machinery).

• Transmission & differential fill/drain plugs.

• Hydraulic system access points.

• Gearboxes, pumps, and industrial equipment.