7.3 Flashcards
What can rules and scales be made of?
Tempered carbon steel or satin finished stainless steel?
What material should you never use a lead pencil on?
Titanium. The carbon can infuse the metal when heated and cause cracking.
What angle is a centre punch?
60 degrees
What materials are coarse saws for?
Soft materials
What is Kerf Clearance
The slot the saw cuts is bigger than the blade thickness (waved blade)
How many teeth in coarse, medium and fine saws?
14,22,32
What angles are triangular files for internal diameters limited to?
60 degrees
What are the 4 file cuts?
Single
Double
Rasp
Dreadnought
What are the 4 grades of cut?
Smooth
Second cut
Bastard
Rough
How far should the bench vice be below your elbow?
5-8cm (2-3 inches)
How should be pressure be applied on very soft materials?
Forward and back stroke
What is pinning?
The clogging of the file teeth
How do you prevent pinning?
Applying chalk, white spirit or oil
What are drills made of?
High speed steels (HSS) or carbon steels
What steel is more economical for drills?
HSS
Carbon steels overheat and lose their hardness when drilling very tough material (but cost less)
What are the twist drill angles?
Lip relief= 12-15 degrees
Lip angle= 59 degrees
Included angle= 118 degrees
What is the land for twist drills?
The peripheral portion of the body between adjacent flutes.
What’s the most common twist drill?
Jobbers drill
How many flutes do twist drills have?
1-4
What is the taper called for taper shank drills?
Morse taper
What should be used with an extension drill?
Drill guard
What sizes do machine spindles come in?
8 sizes numbered 0-7
What angle is often used for extremely hard materials?
Lip angle= 70 degrees
Point angle= 140 degrees
What cutting angle can be used for soft materials or fibres?
40 degrees
What drilling angle for stainless steels or titanium?
140 degrees
What angle for plastic drilling?
30 degrees shallow holes
Up to 70 degrees very deep holes
For standard aluminium alloys, what satisfactory angle?
135 degrees
What’s the metal at the centre of the drill called?
The web
What should the drill speed be limited to for drills longer than 3 inches?
6000 rpm
What angles are available for angle drill motors?
30, 45, 90 (limited access places)
What is a flat offset drilling head also known as?
Pork chop
What is wrong with the speed of drilling if the corners wear away too fast?
Too high
What should very hard steel be cut with?
Kerosene or turpentine
What should be drilled to stop a crack?
1/4 inch counterbore
What does a drill guide do?
Keeps the drill 90 degrees to skin surfaces.
What is the nut plate drill jig known as?
Anchor nuts
What numbers and letters are used for drill gauge sizes?
80-1
A-Z
Why is Boelube good?
Non corrosive and paint compatible
Removed easily with warm water
Non toxic
Compatible with most systems
When should Boelube residue be removed?
Within 48 hours of use
When would a shaft basis system fit be used?
Bearing and gears where a variety of components need to fit one shaft.
How does the ISO system of fits work?
H upwards smaller the hole
h upwards bigger the shaft
What is the standard for ISO system of fit?
British standard 4500
What are reamers for?
Improve the quality of hole and provides closer control of drilling hole size.
How big should a reamed hole be drilled out before?
1/32 under finishing hole size
What are reamers made out of?
High speed steel or carbon steel
What do spiral fluted reamers do which straight fluted do not?
Do not tend to chatter and must be used when cutting reamed holes that have key ways
What are bottoming reamers for?
Complete reaming of blind holes
What do right hand twist spiral fluted reamers do?
Removal of chips affected like normal drill.
What do left hand twist reamers do?
Move chips in advance direction. Does not pull the drill into the hole
What are left hand twist reamers only good for?
Transmissions
How are reamers made to reduce vibration?
Uneven spacing
How do you remove a reamer?
In the same direction as the cutting direction.
What is the advantage of machine reamers?
Higher cutting capacity and dead centre holes.
Why is the pilot chuck reamer the most commonly used?
Accurate lead into the hole and a superior finish
When is an expansion hand reamer used?
When a hole needs cutting a few thousandths of an inch over nominal size for fit purposes
Which reamer is threaded it’s entire length?
Hand taper reamer
What’s used to countersink inaccessible holes?
Back countersink
What is spotfacing?
The method for cutting a hole for a bolt head on an uneven surface.
(Use a pilot 1/32 inch under hole size)
What are the most common threads used on aircraft?
DIN Metric and American National
How is a thread measured below 1/4 inch?
Numbers between 0-12
What parts make up the hand threading tool?
Stock and die
Why does the die of a hand threading tool have 3 or more flutes?
Form cutting edges on the internal thread.
What do regular hand tap sets consist of?
Taper, intermediate and bottoming taps.
What is a torque wrench measured in?
Inch-pounds or foot-pounds
What are the 3 types of torque wrench?
Deflecting beam, torsion bar and toggle
What torque wrench has a pre determined torque set?
Toggle
How frequent must torque wrenches be calibrated if in frequent use?
Weekly
How much can lubrication and frequent affect a torque reading?
25%
What is a torque wrench accurate to?
+-2%
What’s the accuracy of a micrometer?
0.01mm
How much of an abrasive wheel is encased in a wheel guard?
3/4
Why are lubricants used?
Prevent heat build up and increase efficiency.
What is hydrofinishing for?
Remove impurities and make oil brighter.
Why are synthetic oils more advantageous than mineral oils?
Less impurities, more molecularly pure and more thermally stable
What bearings and bushings should not be lubricated?
Teflon
What is the max pressure for applying lubricants?
2500psi
What is suitable pressure for lubrication?
100-200psi
What is bonding?
The electrical interconnection of metallic parts and for the safe distribution of electric charges and currents.
What are used for bonding connections in high vibration areas?
Braided copper or aluminium cords
What does a continuity tester consist of?
Low voltage battery (2.5 volts) and a test lamp
When should a millivolt drop test be carried out?
If there is excessive resistance,… low terminal voltage at connections and heating at conductor joint.
What length show a drill stop be set to in reference to the material?
Material thickness + .10 inch
