A Hex Head Cap Screw with part number 73454 is a common type of fastener, featuring a hexagonal head and a threaded shaft. These screws are designed to be inserted into a pre-tapped hole or used with a nut and are tightened by applying torque to the head. They are widely used in various applications, including automotive and heavy machinery. 

Here's a breakdown of what's typically involved with a hex head cap screw:

• Hex Head:

  The six-sided head allows for easy gripping and tightening with a wrench or socket. 
• Threaded Shaft:

  The screw's shaft is threaded to engage with a pre-tapped hole or a nut. 
• Material:

  They are often made of steel, and may come with a zinc plating for corrosion resistance. 
• Grade:

  Hex head cap screws are available in different grades (e.g., Grade 5, Grade 8), indicating their strength and tensile strength. 
• Size:

  The size is specified by the diameter and length of the screw. For example, a 1/2"-13x1-1/4" screw indicates a half-inch diameter, 13 threads per inch, and a length of 1.25 inches. 
• Usage:

  They are used in a wide array of applications where a strong and reliable fastener is needed.