Fasteners& Common Assembly Components

Types of Fasteners

• Bolts/Screws• Washers• Nuts• Retaining Rings

Types of Bolts for Fastening

Most of the above fasteners require a Clearance Hole and the underside of each fastener’s head sits flush with the surface that the hole is located in.

Socket Head Cap Screws can be used as described above or put in a Counterbored Hole to allow the head of the fastener to sit flush with the surface of the part

Flat Head Screws should be used in Countersunk holes to allow the head to sit flush

Clearance Hole

Counterbore

Countersunk

Bolt for Locating & Fastening

Precision Shoulder Bolt

Precisely ground diameter used for locating and rotational fastening

Washers

Common Assembly Components

• Bushings• Bearings• Retaining Rings

Bushings

• Primary functions are to act as a wear component and to reduce friction

• Usually used where two components are rotating (not constantly)

• Also used to locate other parts (wear item)

• Sleeve Type or Flanged Type as shown

• Common Material types: Bronze (oillite), Brass, Teflon, Plastics, etc.

Bearings

• Each type is designed for different applications (Load Types)

• Ball Bearings are most common• Used when rotating objects are

consistently moving (wheel bearings)

• Each require specific fits outlines by the manufacturer based on the application

Retaining Rings

• Used to secure location along the axis of a shaft

• Commonly used to secure bearings on shafts or in housings

• External or Internal designs, with varying means of insertion and removal

Applying Fastener Knowledge to Manufacturing Class

• Understand the function of the component required; is it simply holding things together or are things locating/rotating around the fastener?

• Be aware of the relationships between fits and fasteners (Clearance holes vs locating/press fits)

• What fastener does the job the best and looks the best? Why have a hex head bolt sticking out when you can use a SHCS?