 |
| ||||||||||||||||||||||||||||||
Screwing is the most common type of joining mechanical or electromechanical components. For making or detaching such joints, screwdrivers and wrenches (spanners) of various types and sizes are used.
Srewdrivers
The types and sizes of screwdrivers required depend on the types of the screw.
Screwdrivers for slotted screws
Figure 1 - Screwdrivers 1 -
1 screwdriver with fixed blade, 2 spiral-ratched screwdriver
Figure 2 - Screwdrivers for
recessed-head screws (Phillips screwdrivers)
When using screwdrivers, attention is to be paid to the following:
- The blades must perfectly fit into the slots of the screws.
- The clearance between the blade and slot must be very small.
- The width of the blade must be slightly smaller than the diameter of the screw head.
Figure 3 - Selection of a
screwdriver - 1 screwdriver blade too small, 2 screwdriver blade too big, 3
correct screwdriver blade
What are the effects when using a screwdriver the blade of which is too small?
___________________________________________________________________________
___________________________________________________________________________
___________________________________________________________________________
Why must a screwdriver with defective handle not be
used?
___________________________________________________________________________
___________________________________________________________________________
___________________________________________________________________________
Wrenches (spanners)
Wrenches differ with respect to their type and (width of) opening.
Figure 4 - Double head
(open ended) wrenches
Figure 5 - Box wrenches
(socket wrenches)
Figure 6 - Ring wrenches
When using wrenches, attention is to be paid to the following:
- Wrenches must suit the width across flats (wrench size) of the screw or nut.
Figure 7 - Wrench with nut -
1 wrench size
Why must the size of the screw/nut comply with the opening of
the
wrench?
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
What tool can be used for slackening a nut if no suitable wrench
is
available?
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
 |
 |
