Final Flashcards
A metals ability to change shape without breaking is called?
Malleability / Ductility
The ability of a metal to return to its original shape after being deformed is called?
Elasticity
Some alloys have better magnetic properties than pure metals, one example is?
Alnico
A solid and a liquid can exist together at the melting point. Adding heat melts…
More of the solid, but does not change the temperature
Alloys that contain iron as the base metal including all common steels and special steels are?
Ferrous alloys
The speed and ease with which a metal can be cut on a machine tool is called?
Machinability
Tensile yield strength is?
The maximum tensile stress a sample of the metal can apply to the testing machine before it begins to deform permanently
Tensile strength formula
At high temperatures, an extremely slow, continuous distortion of certain metals produces another type of failure called?
Creep
What is density
Is the mass of a material per unit of volume
Specific gravity is the ratio between?
The density of a given material and the density of water
Permanent-mold casting uses what kind of cores?
Metal and sand cores
What is centrifugal casting
The process in which centrifugal force makes the metal flow away from the center and against the sides of the mold
What is the most rapid of all castings?
Die casting, it is used in casting metals having no iron in them, non ferrous metals
What is the most common method of cold forging?
Upsetting
What is pulled through a tapered die to form the wire?
A rod
The main difference between cast iron and steel is the?
Carbon content, steels have less than 2% and cast iron has 2% to 4%
An alloy with a high carbon content has a relatively low melting point, which makes it?
Easier to cast than steel
Malleabilized iron is softer and less brittle than white cast iron but?
Has better resistance to wear than gray iron
High-alloy cast iron is used in making parts that must?
Be hard and tough, but not brittle
What are the different steel making processes?
Open-hearth process
Basic oxygen process
Electric furnace process
When making steel, the most important element to be added to iron is?
Carbon
In both AISI and SAE coding systems each code number specifies?
The chemical composition of one kind of steel
The amount of sparking, the length, and color of the sparks and the appearance of any bursts within the sparks will help you identify?
The metal
What is the best grading for cold-rolled sheets?
Commercial quality
How much chromium must steel contain to be considered stainless steel?
12%
What causes weld shrinkage distortion?
Results from the uneven heating and cooling of metal parts during welding
How do you anneal the star drill?
Slowly heat up with oxyacetylene torch
Reach above its critical temperature
Should glow pink
Pack drill into container of hot sand
Allow to cool slowly
Why do you preheat?
To greatly reduce internal stresses that would otherwise build up during welding, as a result little or no distortion will occur during welding
Low carbon steels are more often ____
High carbon steels are often ____
Forged
Cast
Steels containing .55 to 1.00 percent carbon are
High-carbon steels
Cold-working makes the alloys
Harder and stronger
A copper alloy containing a little lead is?
Much easier to machine
What is beta-brass?
Contains 36-50% zinc. And it is harder than alpha brass and less ductile
Which is the strongest of the brasses?
Muntz Metal
The copper alloy most widely used for casting is?
Leaded red brass, aka ounce metal
What happens when aluminum is exposed to air?
An aluminum-oxide coating that forms rapidly on its surface when the metal is exposed to air
What does the first digit indicate when describing alloys
The first digit indicates the main alloying element
What is cladding
Thin layers of aluminum can be rolled into a base metal
Aluminums strength decreases as?
It’s strength decreases greatly as the temperature of the metal rises
Intermediate-temperature solders melt at temperatures?
500 to 700 degrees Fahrenheit
Magnesium is extracted from brines and ores by two methods?
Electrolysis and reduction
The EK, EZ and ZE alloys are used at temps of 300 to 500 degrees Fahrenheit, their high temp strengths are greater than those of?
AZ alloys
What does the letter “a” indicate in alloys?
It indicates an annealed sheet
Magnesium can be gas welded however
It should only be gas welded for emergency repairs and special applications
The usual melting and casting methods cannot be used for titanium the reason being
Melting titanium reacts with gases in the air. Usually an arc melting process is used in an atmosphere of inert gas ( argon and helium )
Various portions of lead and tin are alloyed to make?
Solder
What is lead wool
The lead forms into fine fibers, when hammered into a small space, the fibers become welded together in a solid mass, which seals a space tightly
Nichrome wire is found in?
Toasters
Zinc is widely used as a corrosion resistant coating for steel sheet, called?
Galvanizing
The proper lubricants to use when machining zinc include
Lard oil and kerosene
A liquid has a fixed volume but?
It’s shape can change
What is density measured in?
Grams per cubic centimeter (g/cm3) or in kilograms per cubic meter (kg/m3)
What kind of process is evaporation?
Cooling process
How does the fluid move in laminar flow?
In layers parallel to the pipe
The solubility is usually zero at the ______ point of the liquid
Boiling
How do thermoplastic’s react to temp?
Soften when heated and harden when cooled
What is injection molding
A high speed, low cost method of forming intricate parts
What is a part of filament welding
A glass fiber around a special form called a Mandrel
To avoid chipping or cracking while machining?
Reduce the feed rate just before the drill
Point penetrates the other side of the material
When patching corroded surfaces
Clean both sides of the material
Elastomers have the ability to?
Be stretched to at least twice their original length and then return rapidly to there original shape
Class T for properties of rubber means?
Resist damage by extreme high and low temperatures
Are most rubber compounds flammable?
Yes
The less sulfur used when vulcanizing rubber the ________?
Softer the vulcanized product
The ability to flex is important in what wired insulation?
Extension cords, welding cables and power tool cords
How is a radial cut produced on a log?
Cutting the log lengthwise, with the cut going through or very near the centerline of the log
Measurements of running feet also called lineal feet refer to?
The actual length of the board
The quality of veneer plywood falls under what section
N
What wood is not good for load bearing surfaces?
Wood with many knots , each knot weakens the wood
In softwoods how deep should the pilot hole be?
Only half as deep as the length of the screw
What is air entrained concrete used for?
For building structures exposed to severe cold
Are cinderblocks used above or below ground?
Above ground
Type N mortar is a medium strength mortar used for
Exposed and load bearing clay tile construction
Plaster of Paris sets very quickly, about?
15 minutes, so it can be used only for small patching jobs
Before inserting new glass what should you do?
Place about a 1/16th of glazing compound along the window frame
Convection in fluids is where
The material is free to move around ( gases and liquids )
Mineral wool, has low K meaning it withstands both high and low temps, will not burn, and is chemically inert. It is used in
Ovens, boilers, hot-water tanks, freezers, refrigerators, and air ducts
How can you reduce vibration in rattling pipes or ducts?
By wrapping pipes or ducts with lead sheet or plastic film containing lead powder
An asphalt coating serves as a ______ on the outside of underground or basement walls
Moisture barrier
Mica provides?
Necessary insulation, that being 1580 ( kV/cm )
The liquid part of a paint is called the?
Vehicle, it consist of an oil plus a thinner. The vehicle is also called a binder, because it binds the pigment particles into a uniform film
What is the single most important factor for success in applying a protective coating?
Surface preparation
While blasting cleans a surface to the bare metal. It also?
Completely removes all scale and corrosion and creates the best anchor pattern
What happens in metalizing?
An oxyacetylene flame melts the zinc and sprays it onto the substrate
On the PH scale the numbers below 7 indicate?
Acidity
Why should gasoline never be used for cleaning?
It’s highly flammable
What is sulfamic acid used for?
Removing hard water deposits in heating and cooling systems
Separators or stabilizers called sequestrants prevent?
Scale in piping systems and boilers
Class C fire extinguishers are used for
Live electrical systems
What is curing?
The completion of all chemical and physical reactions that affect bonding
Water-soluble gums and starches from plants are made into natural vegetable glues called?
Mucilage
What is the high strength adhesive joint?
Bevel-lap joint
Rubber tape makes a very good insulating barrier for?
Electrical wiring
What is activated charcoal , sometimes called activated carbon?
A porous material that has a tremendous amount of surface area that can trap other materials
Carbon combines more rapidly with oxygen as temperatures increase but is chemically inert at?
Room temperature
Noise operation with carbon brushes usually indicates?
Brush problems
Why are non porous seals used in refrigeration?
The don’t allow even the tiniest leak in a system where it could be harmful
When installing packing, If there are only 2 rings _______
They should be positioned 180 degrees apart From the joints
How is welding started?
Touching the end of the electrode to the base metal, then lifting the electrode about a 1/4 inch. This action forms the arc which immediately produces temperatures exceeding 11000 degrees Fahrenheit
What does the word shielded in shielded metal arc welding refer to?
The cloud or shield of gas that forms around the arc area as the electrode covering or flux burns away
As the arc length increases what happens?
The resistance increases, thus causing a rise in the arc temperature
What are electrodes classified by?
Their core material
A welding helmet with a least a number ____ filter must always be worn while arc welding for protection against the arc flash and weld spatter
9
The type of covered electrode chosen for a given job depends on many factors, some of the most important are?
The composition of the base metal
The aws system uses the letter “E” for arc welding electrodes, in a four digit number the first 2 digits indicate?
The tested minimum tensile strength of the deposited metal
The current range for a particular electrode depends on its?
Diameter
Iron-powder electrodes have very thick coverings that contain between 25 and 50 percent iron powder. The thick cover allows?
You to use high welding amperage’s without causing excessive penetration
Electrodes with cellulose coverings need?
A certain amount of moisture to function properly
When metal is transferred from the electrode to the base metal by a series of rapid make and break short circuits it is called?
Short-circuit transfer, when the electrode touches the base metal a short circuit is created
The most common shielding gases used in GMAW are?
argon, helium, and carbon dioxide
Argon gas is heavier than air, this characteristic is advantageous because?
It readily settles and spreads when flat or horizontal fillet welding
In GMAW the main consideration when selecting a wire is to make sure that?
It has the same composition as the base metal
To start the arc and glad flow you?
Press the gun trigger, hold the gun nozzle about 5/8 to 3/4 in. above the work and tilt it about 20 degrees off vertical in the direction of welding
A GTAW torch holds?
The non consumable tungsten electrode in a collet, the torch nozzle guides the shielding gas into and around the area. Some torches are air cooled and others are water cooled
GTAW electrodes
The only purpose of the tungsten electrode is to serve as an electrical conductor to carry current to the welding arc
Helium produces a hotter arc than argon, this allows
Faster welding speeds, provides deeper penetration and produces a narrower heat affected zone in the base metal
Low carbon steel is the proper filler metal for welds in?
Low carbon steels
ACHF is preferred for aluminum because?
The arc action breaks up the surface oxide
The GTAW process using DCEN is one of the best for?
Welding stainless steels
How does resistance welding work?
Each process uses pressure and electric heat to join metals
How does submerged arc welding work?
A layer of powdered flux pours into the joint just ahead of the arc, the flux completely covers the arc and the molten metal to protect them from air. When melted the flux becomes electrically conductive and the welding current flows through the flux
How does PAW work?
The arc from the tungsten electrode heats and ionizes a gas, the result is a narrow concentrated arc column called a plasma jet that comes out of a small opening in the torch nozzle
There are three forms of friction welding, the first is?
Conventional friction welding, the machine presses the two parts together and rotated one part
One advantage of Ultrasonic welding is that?
The process can be used to make leak tight joints in thin materials
What is the heat affected zone?
The area around a weld that does not melt but gets hot enough to change its mechanical properties
When should you post heat?
If the structure cools too fast, the metal does not cool evenly, putting stress back into the metal
Whether or not you pre heat depends on?
The thickness of the part
Ferrous metals are iron based metals, the need to preheat them depends primarily on?
Their carbon content
For edge preparation you will have to?
Cut it gouge the base metal in almost every case
What is the most common process used for welding cart irons?
SMAW
What are nickel based electrodes
Stable at low currents for welding in all positions
What process should you use when welding with low hydrogen for alloy steels
DCEP current
Aluminum combines readily with ______ to form an oxide coating on its surface
Oxygen
What’s the best way to identify non ferrous metals
Contact the parts manufacturer
What is air carbon arc cutting
The most widely used arc cutting process is an air carbon arc, it can be used to cut or gouge nonferrous or ferrous metals
Why is chemical cleaning of aluminum better than mechanical brushing?
Because re-oxidation is less rapid
Welding nickel, what is the most common process?
GTAW is the most common process, Use a 2 percent thoriated tungsten electrode and a DCEN power supply
Welded joints are better than other types because?
They are stronger, more compact, lighter in weight, and require less maintenance
What is AR-1?
It applies to systems requiring the highest degree of weld quality, including nuclear energy, space, high pressure, high temperature, chemical or gas applications
The process most widely used to weld pipe is?
SMAW
What is the purpose of backing strips?
Ensures full penetration and prevents icicles
The need for preheating and post heating pipe depends on the same factors as those for plates or castings…?
The base metal composition and thickness
What is abrasion?
The grinding or scratching action of hard particles
What does cross checking do?
Relieves residual stress in the deposit
What are the hardest and most wear resistant hard facing alloys?
Tungsten carbide
Oxyacetylene hard facing is the best process to use for?
Thin edged tools
Automatic hard facing machines are usually what type?
SAW
What is a type of milling machine
Ram and turret, sometimes called tool-room type
In machining the table moves from side to side, this is called?
Longitudinal motion
What can you use to keep or stop your work piece from shifting under the cutting forces?
A kicker
The style C arbor is used for what?
Mounting shell end mills
The cutting speed recommendations for milling cutters are in?
Surface feet per minute ( sfpm )
In angular indexing you use degrees instead of the _______?
The number of indexes, for example when set up at a 5:1 ratio, each turn of the crank turns the workpiece 72 degrees or 1/5 of a circle
Why would you want to use a hard work piece material like cemented carbide or ceramic cutting tools ?
Both permit much higher cutting speeds than high speed steel tools, you generally don’t need ceramic tooling unless you are machining carbon steel , alloy steel, gray cast iron or stainless steel. Even then you can get by using high speed cutting tools if you decrease the cutting speed and feed rate
In shaper operations, the speed of the cutting tool as it travels through the workpiece is the?
Cutting speed, it is expressed in surface feet per minute ( sfpm )
Carefully check the alignment of the vise and the shaper ram, what is the best instrument for this?
A dial indicator
When making internal key ways the most important dimension is?
It’s width
Factories still use planers when they want a surface that will be?
Hand finished
As the grinding wheel wears further, the grains tear away from their setting. This does what?
Exposes new grains
What are the two types of surface grinding machines?
Planer and rotary
To cut efficiently, a wheel with a glazed or loaded surface requires?
Dressing, dressing is removing the glazed or loaded surface to expose new, sharp abrasive grains
Why would you let the grinding wheel run awhile after you turn off the coolant pump?
To throw off any coolant left on it
The most common type of gear, and the easiest to make is the?
Spur gear
What gears are the most used in plant machinery?
Spur gears and straight bevel gears
What is diametral pitch
The ratio of the number of teeth to the number of inches in the pitch diameter
When you have finished cutting the first full tooth what do you do?
Check it with a gear tooth vernier caliper
In an involute rack the pitch line is?
A straight line
Bandsaw blades tipped with tungsten carbide are usually used to cut?
Thick work ( 3 in or more )
Tungsten-carbide blades are normally…
Coarse in pitch
Blades for grinding, polishing, and filing are different because?
Their cutting surfaces are flat
Because band saw blades operate at relatively high surface speeds it is usually necessary to provide?
Some type of cutting fluid
The vertical type band saw is best suited for cutting?
A wide variety of shapes or contours in almost any material
The rate of heat input from the oxy-fuel flame is controlled by?
The speed with which the torch is moved
In torch brazing how is the filler metal distributed?
By capillary action between the close fitting surfaces of a joint
What do fluxes do?
They also act as cleaning agents to dissolve oxides, release trapped gases and slag and help clean the metal for welding
How do you weld low carbon steels with a oxy-fuel torch?
The molten weld puddle must be kept covered by the envelope of the flame throughout the welding process. The molten metal oxidizes rapidly if air is allowed to contact the weld puddle
What is thermal conductivity
Applied heat spreads rapidly through the mass of parts to be welded, requiring more heat to be applied at the joint
Mechanical cleaning includes…
Grinding, wire brushing, filing, scraping and buffing
What’s very important in welding brass
Flux
When Welding lead what should the torch be set to?
It should be adjusted for a neutral or slightly carburizing flame
What should the torch be set too when welding nickel
Adjust the torch for a slightly carburizing flame
When welding magnesium what should the torch be set to
Adjust the torch for a neutral flame, and then add a slight excess of acetylene to the flame gas mixture
What’s an important rule to make optimum welds?
Know what you are welding
Equipment setup, adjustment, and operation are the same for oxygen cutting and oxy fuel welding. Both the cutting torch and the welding torch are ignited with a?
Sparklighter
The minimum PPE for oxy fuel cutting operations are?
Gloves, and welding goggles with a suitable shade of darkened lens
What is scarfing?
A cutting operation in which surface defects are removed from unfinished steel
How can you cut difficult metals with a oxy fuel torch?
Introduction of iron or mild steel as a cutting catalyst
In what process is filler metal distributed between joint surfaces by capillary action?
Brazing
Define what brazing filler alloys and fluxes do
Material used to prevent, dissolve, or facilitate removal of oxides and other undesirable substances
Why is close temperature control very important when brazing aluminum?
Aluminum alloy filler metal melts just before the base metal melts
Why should you be very careful when dealing with fluxes?
Many are harmful to the skin, throughly flush the effected areas if in contact
What is solder?
Relatively low temperatures, always below 800 degrees Fahrenheit. Soft solders are not to be confused with hard solders ( brazing alloys )
What are surfacing processes used for?
Used to repair worn or damaged machine parts. These processes are often referred to as hard facing
What is thermal spraying
A process in which special metallic or non metallic coatings are sprayed onto the surface parts
What is the torch hard facing procedure?
When the base metal starts sweating, move the rod into the center of the flame so that drops of the filler rod are melted off and fall into the sweated zone
The material in the flame spraying process is fed into the flame, melted and expelled from the gun by a?
Stream of compressed air
What are some common surfacing materials
Ceramics
When you thermal spray for shaft repairs what is the next step?
Machine the damaged area to remove any ridges or burrs
Electric arc spraying applications require lens shade numbers from?
9 to 12
What is the only purpose of a filler rod
To supply filler metal to the joint
In what welding process do special materials in the electrode coating create a gaseous cloud that shields the arc area from atmospheric contamination
SMAW
What type of weld is triangular in cross section and used in joints that have two surfaces approximately at right angles to each other?
Fillet weld
What are the parts of a weld?
Toe, root, throat
What is joint fit up?
Joint alignment, spacing, and edge preparation
What is a good house keeping rule for welding?
Do not allow hoses and cables to cross areas where people walk
Always keep all _____ out of the welding area.
Combustibles
When working with fumes and gases what should you do?
Never position your head directly over the fumes or gases, hold it off to the side
What are some protective clothing items you should wear when welding?
Sturdy leather or canvas gloves
If regulator connections still leak after reasonable tightening what should you do?
Have a qualified technician check the regulator
Oxy fuel welding outfit includes a
Torch
As and added protection against flying sparks what should you wear?
High cut work shoes or boots
What is one step when assembling and setting up an oxy fuel welding outfit
Crack the cylinder valves momentarily to blow out any dirt or dust that might have collected inside the valve outlet
What is a characteristic of a neutral flame
Brilliant white cone inside a blue envelope
How should you shut down the gas cylinders in an oxy fuel setup
Close the oxygen control valve on the torch first, then close the fuel gas control valve
How are oxy fuel and arc welding processes similar?
The procedures leading up to the actual joining operation are also comparable
In straight polarity ( DCEN ) how do electrons move
They move away from the electrode cable
In DCEN the electrode cable is connected to?
The negative and in DCEP it is the opposite
Plants use what kind of machines for average or general purpose maintenance?
250 to 350 Amps
In GTAW process what makes it different than SMAW
The electrode is not consumed as it is in SMAW processes
What tools are useful for welders
The chipping hammer
What are the pros of oxy fuel welding
The equipment is inexpensive and does not require external power
What welds are easiest to make?
Welds in the flat position , flat position is any work done above the piece
Horizontal welds are done from the?
Side
What welds are the most difficult?
Overhead welds, because they are made from underneath the weld
What is one step in SMAW preparation?
Obtain the necessary safety and protective equipment
How do you weld in GTAW?
Maintain and 1/8th in arc length, tilt the torch 15 degrees from vertical
Too high a current produces what kind of welds?
Large and irregular weld beads
To eliminate arc blow completely what can you do?
Change to A/C power
What causes brittle welds?
Brittleness in metal results from too rapid or excessive heating and cooling
Uneven expansion and contraction in the heat-affected zone near a welded joint can cause?
Metals to buckle,warp or crack
The visual and magnetic reaction tests can be made without?
Disturbing or destroying the base metal
Dimensions of the chamfer and the weld cross section are written how?
To the left of the weld symbol
For turning operations, the carriage is connected to the?
Feed rod
The lathe is expressed in two dimensions, both are given in inches. The first describes the _______
The swing, or diameter of workpiece the lathe can rotate
Use a Chuck to hold workpieces for any of the following lathe operations…
Turning
Facing
Drilling
Boring
Reaming
Threading
The inside of what piece of equipment is shaped to fit a particular type of stock?
Collet
What is a steady rest?
Supports the end of a very long workpiece
What does the follower rest do?
It follows the cutting tool
Hold all irregular or odd-shaped stock on a?
Faceplate or in a chuck
Mild steel cutting speeds for finishing cuts is?
125 sfpm
The smoothness of the finish depends a great deal on how?
Sharp your bit is and how fast your feed rate is
Like boring, reaming is used to?
Produce a fine finish in drilled holes
The principal part of a twist drill are?
The body, the shank, and the point
Recommended drilling speeds for high speed drilling of wood is?
300 to 400 sfpm
Note that the speed in feet per minute is multiplied by 12 to change it to?
Inches per minute
Boring is the process of what?
Making a hole larger
In a vertical turret lathe, an overhead ram advances?
The boring tool into the work
What is the land?
The metal between the flutes
Where a very accurate hole is required, what is recommended?
Hand reaming the hole
A tapered hole through the shell allows you to what?
Mount the shell on a tapered arbor
How do you make a reamer in emergency situations?
Use a drill and round off the corners of the bit with an oil stone
A burr on the edge of a reamer can spoil the hole, if you notice a burr on the cutting edge or land of a tooth smooth it off with a?
Oilstone
Counter sinking allows for?
Flush fitment of screw heads
The most common form of precision threads for moderate power transmission needs is?
The acme thread
Use a flute less tap only for?
Ductile materials, like aluminum, brass, and copper
How do pipe threads work?
They permit a tiny leak through the spiral tunnel
When selecting a tap for most work what type would you use?
Spiral point or gun tap is ideal
Why do you occasionally turn the tap back a half turn?
To break long chips
Iron parts are usually made from?
Castings
In the SAE code the last two digits indicate?
The carbon content of the steel in hundredths of one percent
What is hardness?
The ability to resist cutting, scratching, and penetration ( most steels )
Cooling or quenching leaves steel hard and brittle, the steel can break if exposed to a sudden temperature drop. To prevent this what can you do?
Apply another heating and cooling process called tempering
Use a brush to remove the discontinuous or flaky chips produced by?
Cast iron
What can you use to also lay out and measure distances?
Dividers
Why do you coat cast iron plates lightly with oil?
To prevent rusting
A surface gauge may not be high enough to make layout lines on a large workpiece. In this case use?
Box parallels
The straight line distance between the centers of any two adjacent holes is a?
Chord or pitch chord
Why should you not carry tools in your pocket?
You can jab your hand reaching for a tool, or you can fall and stab yourself. Carry tools in a tote or in a pouch fastened to your belt
The center in the tailstock is called the dead center because?
It is not driven
What do you use to remove a live center from the spindle?
A knockout bar
In boring operations you do not need a tail stock as it would be in the way of the tool. The ( live ) headstock center isn’t used either. Hold workpieces to be bored in?
A chuck
To remove a chuck from a lathe use?
A block of wood
What holds workpieces during various machine tool operations?
A vise
One view looks as though a portion of the part was cut away to show how the inside looks. This view is called a?
Section
What is the second most common shape found on nearly all parts such as a shaft, bearing, or hole?
Cylinder
What is precision?
The degree of accuracy needed for a part to function properly
Each revolution of the thimble moves the spindle how much?
1/40th of an inch , 0.025
What do toolmakers use gauge blocks for?
To check gauges and lay out and set up work requiring extreme accuracy
High-speed steel gives off what kind of sparks?
Dark red sparks
What is the base of the shank?
It is the surface that supports the cutting tip
Do not grind on the side of the grinding wheel , only grind on the?
Face
In grinding wheel marking codes the first symbol is the?
Abrasive type
The grinding wheel does not produce a perfectly smooth edge, therefore you should?
Hone the cutting edge after grinding tools
The metal column that separates the flutes is called the?
Web
The shape of a drills point is very important, most general purpose twist drills have an included angle at the point of how many degrees?
118
What relief is used on a flaring cup grinding wheel?
A flat relief
Machine countersinks have an included angle of how many degrees?
60 to 82
When do you use a tapered reamer?
To remove burrs or nicks in machine spindles
