7.3 Flashcards
Torque wrench continued.
M1 = M2 x L1 / L2
Prick punches
Sharp tip ground to an angle of 30 or 60 degrees.
Eye protection must be worn.
Used when marking up a piece of metal.
Centre punches.
Ground to 60 degrees for light work or 90 degrees for general work.
Generally made of hardened steel but can be copper or brass.
Must be handled with care to not distort the surrounding metal.
Automatic centre punch
Uses a spring.
Starting (taper) punch
Used to drive out a pin
Parallel pin punch
Have a parallel shank.
Diameter sized to match rivet shanks.
Structure must be supported on both sides to prevent bounce back.
Roll pin punch
Used to remove roll pins.
Beryllium-copper , and brass punches.
Used where there must not be a risk of sparking, e.g. fuel tanks.
Why must eye protection be worn when using. A punch?
The bur can split and chip
Aviation hand snips. Their colours and meaning
Straight snips
- cutting straight lines
- cutting outside of a curve.
- yellow
Green snips
- curve right
Red snips
- curve left.
Prefered TPI of a hacksaw for cutting steel?
14 (course)
18 tpi hacksaw, what are they used on and how are they classified.
Course
Prefered for solid state aluminium, bearing metal, tool steel, cast iron.
24 tpi hacksaw, used for and classification?
Medium
Thick walled tubing, pipe , brass , copper, angle iron.
32 TPI hacksaw, used for and classification?
Fine.
Thin walled tubing and sheet metal
Which way do the teeth point on a hacksaw
Away from operator.
In cutting direction.
Junior hacksaw
Teeth point towards the operator because the frame is springy.
Rectangular files
- flat or hand
- rectangular and tapered.
Hand files only have teeth on one edge.
Square files
Double cut teeth on all 4 sides.
Angle of teeth on single cut files
65-85
Angle of teeth on double cut files
70-80
And
40-50
Filing techniques
Smooth finish - draw filing
Straight file
Cross file
Types of pneumatic drills
Pistol grip drills
Straight drills
Right angle drills
45 degree drills
Drill terminology
Flute
Margin
Land
Body
Cutting edge
Flute = removal of scarf and allows cutting fluid
Margin = keeps drill aligned during operation, determines size of drill.
Land = provides torsional strength
Body = between the point and shank
Cutting angle of drills for cutting aluminium or mild steel
118 or 135 inclusive.
Point angle for drills for cutting plastics
30 to 70 degrees
Jobber HSS
Most common drill bit for everyday use
Cobalt drill bits
Heat resistant on hard materials
Carbide drill bits
Most expensive but most durable.
Standard / plain countersink tool
Impractical as dont know depth
Standard countersink with pilot
Guides it into material.
Still impractical
Micro stop countersink tool
Controls depth.
Keeps cutter perpendicular to surface.
Cutters available for 82, 100,120 degree rivet types.
Spot facing
Method used for cutting a flat area or seat for a bolt head or nut on a contoured or uneven surface.
Done on a pillar drill where possible.
Reamers
Used to smoothen or enlargen holes
Thread cutting
Taper tap to start, followed by plug tap , then bottoming tap.
What are dogs
Dogs are used to hold an oddly shaped piece of work.
How do you test an abrasive wheel
Tap gently with a non-metallic object, should give a clear metallic ring.
Nut plate drill jig
Designed for accurate drilling of rivet holes for anchor nuts.
When is a hole finder used
When replacing old skin with a new skin
When is a rivet shaver used
trims mandrel of cherry rivets
Metric micrometer
Pitch of thread is 0.5mm.
Rim of thimble divided into 50 increments. = 0.01mm
Imperial micrometer
Pitch of thread is 40tpi.
One revolution of thimble advances spindle 0.025 inch
Lines on thimble = 0.001 inch
type 1 torque wrenches
Indicates the torque via a mechanical scale or dial or electrically, so it is up to the user to decide when adequate torque has been applied.
Type two torque wrenches
Fixed or adjustable to. A preset torque value, once the value is reached it is indicated by feel or by audible or visible indication.
