Hand Tools

1
Hand Tools
2
Definition

• Hand tools can be described as any device placed
  in the hand and powered by hand to complete tasks
  and help make a task easier, more efficient
  and/or safer.

3
Four Tool Principles

• Selection
• Use
• Care
• Storage

4
Hand Tool Safety

• Hand tools are often underrated as sources of
  potential danger. Hand tools may look harmless,
  but they are the cause of many injuries.
• Eight (8) percent of all workplace compensable
  injuries are caused by incidents associated with
  hand tools.
• Injuries can include sever disabilities.
• Proper evaluation of a hand tools may include
  characteristics such as the task, tool,
  workstation, and end-user.

5
Types of Injuries

• Cuts, abrasions, amputations, and punctures.

Hand tools are designed to cut or move metal and
wood, remember what a single slip can do to
fragile human flesh.
Repetitive motion injuries.
Using the same tool in the same way all day long,
day after day, can stress human muscles and
ligaments. Carpal tunnel syndrome (inflammation
of the nerve sheath in the wrist) and injuries to
muscles, joints and ligaments are increasingly
common if the wrong tool is used, or the right
tool is used improperly.
Continuous vibration
Causes numbness or poor circulation in hands and
arms.
Flying chips of wood or metal are a common
hazard, often causing needless and permanent
blindness.
Eye injuries.
Broken bones and bruises
Tools can slip, fall from heights, or even be
thrown by careless employees, causing severe
injuries. A hammer that falls from a ladder is a
lethal weapon.
6
Injury Examples
1. Loss of eye/vision
Using striking tools without eye protection.
2. Puncture wounds
Using a screwdriver with a loose handle which
causes the hand to slip.
3. Severed fingers, tendons and arteries
Dull knife
4. Broken bones
Using the wrong hammer for the job and smashing a
finger.
5. Contusions
Using a small wrench for a big job and bruising a
knuckle.
7
Hand Tool Safety

1. Safety is a state of mind. Always think when
   using a tool.
2. Every tool was designed to do a certain job. Use
   it for its intended purpose.
3. Keep your tools in good condition sharp, clean,
   oiled, dressed and not abused.
4. Worn tools are dangerous.
5. Tools subject to impact tend to "mushroom, keep
   them dressed.
6. Use tool holders.
7. Do not force tools beyond their capacity or use
   "cheaters" to increase their capacity.
8. Secure your work in a vise whenever possible.
9. Chisels, screwdrivers or other pointed tools
   should never be carried in clothing pockets.
10. Cutting tools should be kept sharp to ensure good
    smooth cutting. Always use proper handles.
11. Drill Bits should be kept sharp, not dull,
    chipped, rounded, or tapered.

8
Hand Tool Safety--cont.

• 12. Screwdriver points should not be badly worn
  and handles should be in good condition.
• Wrenches, if adjustable, must work freely and
  adjust properly.
• Always wear the PPE required for the job.
• Cut in a direction away from your body.
• Keep close track of tools when working at
  heights. A falling tool can kill a co-worker.
• Pass a tool to another person by the handle
  never toss it to them.

9
Selection of Hand Tools

• The correct tool must be selection for the job.
• Improves longevity of tool.
• Reduced chance of injury to operator.
• Improved quality of results.
• The correct tool is one that was designed for the
  work.
• You should not use a hatchet to chop down a large
  tree.
• A hammer should not be used with a plastic
  handled wood chisel.
• A screwdriver is not a pry bar.
• The correct tool is also one that fits the hands
  and abilities of the user.
• Higher quality of construction will lead to
  longer life and higher quality of work.

10
Use of Hand Tools

• Because the working part of many hand tools are
  close to the hands and other body parts, correct
  uses is important.
• Always cut away from body
• Use two hands if tool is designed for it.
• Keep hands clean and especially free of oil or
  other slick substances
• Insure handles are tight
• Keep focus on the activity.
• Each hand tool was designed for a specific
  purpose. Not using it for that purpose
  constitutes misuse/abuse, which increases the
  risk associated with its use.

11
Care

• Many hand tools are precision devices and should
  be cared for according.
• Steel must be protected from rusting.
• Wooden parts must be protected from water.
• Dulled edges must be sharpened.
• Rivets, screws, etc. must be kept tight.
• Handles should be tightened when loose.
• Wooden handles should be replaced when cracked.
• Dont place tools on concrete floor.

12
Storage

• The goal of storage should be to maintain the
  condition of the tool.
• Hand tools that are organized and stored
  correctly are easier to find, harder to damage,
  and easier for students to put back when they are
  done.
• Cutting edges must be protected from contact with
  hard surfaces.
• Tools must stored so that hand does not contact
  sharp points and edges when removing the tool
  from storage.
• Organize tools by subject matter area.
• Lock tool storage when not being used.

13
Tool classification

• It is a common practice to classify hand tools by
  their function.
• Agricultural Mechanics--Fundamentals and
  Applications
• 1. Layout and measuring
• 2. Cutting
• 3. Boring
• 4. Driving
• 5. Holding
• 6. Turning
• 7. Digging
• 8. Other

14
1. Layout and Measuring Tools

• Layout and measuring tools may be measurement
  transfer tools or have scales for determining
  distances.
• Transfer tools are used to transfer a measurement
  from one point to another.
• May not know or care what the dimension is
• Dividers
• Calipers
• T-bevel
• Measuring tools have a scale that can be used to
  determine a dimension, distance, or angle.
• US tools use fractional scales. Must know how to
  add and subtract fractions.
• Rules
• Squares
• Measuring tapes

15
2. Cutting tools

• Cutting tools are used to cut, chop, saw, or
  otherwise remove material by shaping.
• Saws
• Chisels
• Planes
• Axes
• Cutters

16
Cutting Tools-cont.

• Three common principles of cutting tools.
• Two (2) types of edges, three (3) shapes
• The best cutting angle is determined by the
  hardness of the material.
• The correct speed of cutting is determined by the
  hardness of the material.

17
Cutting Tools-cont.

• Types 2 Bevels and 3 Shapes (6 possible
  combinations)
• Single bevel used to make fine slices or cuts
• Double bevel used to chop or make courser cuts
• Straight shape general purpose shape Coarse cuts
  but more durable cutting edge
• Concave shape finer, more accurate cuts, less
  durable edge
• Convex edges Very durable edge, combination of
  cutting and splitting
• Hollow ground shape is a combination of two
  shapes

18
Cutting--cont.

• The best cutting angle is determined by the
  hardness of the material.
• The harder the material--the smaller the cut
• Requires small chip clearance
• The softer the material--the larger the cut
• Requires larger chip clearance
• The correct speed of cutting is determined by the
  hardness of the material.
• The harder the material the slower the speed
• The softer the material the higher the speed
• Note All cutting tools are designed to cut
  material that is harder than skin and flesh.

19
Cutting-cont.

• Calculating cutting speed is a opportunity to
  include math.

Example
Determine the recommended rpm for a 3/8 inch
drill for cutting mild steel.
20
Calculating Drilling Speed1

• Drilling speed includes the rotational speed of
  the drill (sfpm) and the rate that it passes
  through the material (ipr).
• The ideal drilling speed is determined by the
  hardness of the material.

Material sfpm ipr Feed x 10 E-3
Low alloy steel 50 - 60 3 - 7
Stainless steels (soft) 70 - 90 2 - 6
Stainless Steel (hard) 50 - 60 3 - 7
High Strength Steels 30 - 40 1 - 4
Aluminum 175 - 400 2 - 7
Copper 100 - 250 1 - 5
Cast Iron 75 - 150 1 - 5
Low Carbon Steel 80 - 100 3 - 10
Thermoplastics 100 - 150 2 - 15
Thermosetting Plastics 100 - 150 3 - 8
1For drills 1/8 - 1/2 in diameters
21
Example Problem

• Determine the rpm for a 3/8 inch drill for mild
  steel.
• Mild steel sfpm 90