Hexagon socket oil plug screw

冷镦加工是一种少切削或无切削的压力加工新工艺
金屬。它是一種利用金屬在下列因素作用下產生塑性變形的加工方法
外力作用下，在模具的幫助下，重新分配和轉移金屬的體積，以形成
所需的零件或坯料。冷镦工艺最适合生产标准的
螺栓、螺絲、螺帽、鉚釘和銷等緊固件

A Hexagon socket oil plug screw, commonly known as a hex plug, Allen plug, or socket head plug, is a type of threaded fastener used to seal or close off a threaded opening, typically in machinery, hydraulic systems, or plumbing applications.

Key Characteristics:

1. Hexagonal Socket Drive:

   • Has a six-sided internal recess for secure engagement with an Allen wrench or hex driver.

   • Allows for high torque application without cam-out (unlike Phillips or slotted screws).

2. Threaded Body:

   • Made with external threads (metric, UNC, UNF, NPT, BSP, etc.) to match the threaded port.

   • Some have tapered threads (NPT/NPTF) for a pressure-tight seal, while others use straight threads with a sealing washer or O-ring.

3. Materials & Finishes:

   • Common materials: Carbon steel, stainless steel, brass, aluminum, or nylon.

   • Coatings: Zinc plating, black oxide, anodizing, or PTFE coating for corrosion resistance.

4. Sealing Mechanism:

   • May include an integrated O-ring, copper washer, or bonded seal for leak-proofing.

   • Some rely on thread sealant (Teflon tape, Loctite) for additional sealing.

   • Hexagon socket oil plug screw

5. Head Styles:

   • Flush head (countersunk for a smooth surface).

   • Raised head (protrudes slightly for easier access).

   • Vented head (with a small hole for pressure equalization).

常見應用：

• Sealing hydraulic/pneumatic ports, gearboxes, engine blocks, and fluid reservoirs.

• Acting as drain/fill plugs in automotive and industrial systems.

• Providing access points for maintenance in machinery.

Variants:

• O-Ring Hex Plug (with built-in rubber or Viton seal).

• Metric/Inch Hex Plug (thread size variations).

• Magnetic Hex Plug (captures metal debris in oil systems).