Mechanical Joining Processes

Question 1

What is a screw?

Answer 1

a threaded component which locks into a tapped hole (either premade or self made) to form a connection

Question 2

What is a bolt?

Answer 2

a threaded component which passes through an un-tapped clearnace hole and is secured with a washer and nut

Question 3

What is a washer?

Answer 3

A flat ring that sits between the nut/ bolt head and the surface of the material to increase friction and improve the connection

Question 4

What is the Pitch of a thread

Answer 4

the distance of one thread (distances between too roots or crests the lowest and heighest points on the thread)

Question 5

When should standard Course threads be used?

Answer 5

when 3 full turns of engagments are possible

Question 6

When should fine pitch threads be used?

Answer 6

when less than 3 turns of engagment is possible or high vibration is expected

Question 7

describe the Advantages and Disadvantages of screws, nuts and bolts

Answer 7

ADV :easy to assembly and dismantle, predictable strength, robust
DIS: can undo themselves under vibration, need acess to install

Question 8

Why are machined threads weaker than rolled threads ?

Answer 8

the crystal structure is interupted allow stress concentrations to pull crystal layers apart

Question 9

What is a Quater turn fasterner

Answer 9

A special screw type device whicch undoes quickly with a 1/4 turn

Question 10

What are Spring Fasteners?

Answer 10

slotted or coiled curved sheets of metal which can be inserted into clearance holes and expanded outwards to form a connection

Question 11

What is a split pin fastener?

Answer 11

A special type of nut (a castle nut) which attaches to a bolt and is locked in place with a pin which splits apart, rapping around the nut and locking it to the bolt

Question 12

What are dowels?

Answer 12

simple or tapered cylinders which sit in precision holes helping parts aling together and strengthening their connects

Question 13

What is a cotter pin?

Answer 13

A tapered cylindrical pin which sits in a tapered hole with the small end locked in place with a nut

Question 14

What is a hot riveting?

Answer 14

a metal pin with either a countersunk or mushroom head is heated to be maneable , inserted into a hole and hammered flat forming a shear resistance connection

Question 15

What is a cleco fastener?

Answer 15

a temporary pin rivet connection which holds a part together and correctly aligned during assembly

Question 16

What is a Pop/Blind Rivet?

Answer 16

a hollow rivet with a pin is inserted into the hole. the pin is withdrawn squishing the length of the rivet flat forming a connection when the other side is inacessible

Question 17

What is a shrink fitting

Answer 17

A component is placed into a hole which has been expanded with high temperature. the part is allowed to cool causing it to contract around the component creating a near zero tolerance fit

Question 18

What is spring fastener?

Answer 18

rings of metal which can deform elastically during assembly then snap back into shap for a strong connection

Question 19

What are interlocks and snap locks?

Answer 19

Sheet metal is bent into corresponding hook shapes which clip together connecting the parts