Intro to Machine shop final
Define semi-precision measurement. - A measurement when tolerances or levels of desired accuracy are no finer than 1/64 or 1/100 inch, 0.5 mm, or 1 degree.
What is comparison/comparative measurement? - A measurement that compares the specification of a part feature to a known standard size, as when using fixed gages.
List three rules to follow when using - Do not pile measuring tools on top of each other or drop them, keep them away from moving parts of machinery and metal chips. Use measuring tools only for their intended purposes. Unintended use and abuse can cause damage and make tools unreliable or worthless.
Storing semi-precision measuring tools. - When not in use, measuring tools should be cleaned and gently stored in safe locations away from moisture to prevent rust. A light application of appropriate lightweight lubricating oil can help prevent rust.
What is the smallest graduation on an English (inch) fractional rule? - 1/100
What is the smallest graduation on an English (inch) decimal rule? - 0.010
List three key points in caring for precision measuring tools. - Both the measuring tool and the part surfaces to be measured must be clean of debris and free of any rough edges, Calibration, that is known to be properly functioning and accurate, and making adjustments if needed. It is good practice to store precision tools away from dust, dirt, and moisture and to store them so that they do not touch other tools.
What type of fixed gage can be used to check hole diameters? - Precision fixed gage
What type of fixed gage can be used to check a threaded hole? - threaded plug or pin gage
How is the “go” member of a go/no-go ring gage set identified? - The go ring gage identifiable by there not being a groove around its circumference.
What type of fixed gage can be used to check external threads? - Thread ring gages
What is quality assurance? - An overall view, commitment, or plan for meeting customer demands.
What are the four basic parts of a process plan? - Material selection, machine selection, tooling selection, speed and feed calculation
Briefly define quality control and explain its purpose. - The actions of inspecting the dimensions of machined parts to make sure tolerances are met.
Briefly explain the purpose of a sampling plan. - A quality control guideline that states how many parts should be inspected from a given batch of parts or during a given time period.
What is the purpose of an inspection plan? - A quality control guideline that indicates what dimensions of parts to inspect and what measuring tools and processes to use during inspection.
What is the difference between ferrous and nonferrous metals? - Containing iron and metal that contains no iron
Briefly describe an alloy. - A homogeneous combination of two or more metals or a metal and a nonmetal element.
Name three alloying elements added to steel. - chromium, manganese, molybdenum, nickel, tungsten, and vanadium.
Explain how steel carbon content affects hardness and ease of machining. - Careful consideration needs to be taken when deciding how to machine CRS to minimize distortions.
What is cast iron? - Ferrous metal with carbon content between 1.7% and 4.5%, recognized by a rough scaly surface.
Briefly define the term heat treatment. - metals is the controlled heating and cooling of metals to change their properties. It can be used to make the material harder, tougher, softer, more stable, or more easily machined.
Direct hardening can be performed on steel containing at least ____________ carbon. - 0.3%
____________ is the rapid cooling of metal during heat treatment. - Quenching
What type of hardening operation that leaves the inner core in a softer condition is sometimes performed on medium-carbon steels? - Surface hardening
In what two ways can the process described in the previous question be accomplished? - Case hardening and Carburizing
Why is a routine maintenance plan important? - So the machinery stays in proper working order and operates safely to prevent injury.
What are lubricants - greases and oils
What are lubricant purposes? - used to minimize friction between moving machinery parts. Their use is vital, so machinery operates as intended, and prevents seizing of those moving parts.
List three methods of applying lubricants to machine tools. - Reservoirs, oil cups, ball oiler
List two components of machine tools that should be periodically inspected for wear. - belts and gears
Briefly describe a gib. - A tapered wedge found on dovetail-shaped slides that can be used to tighten the slide as the dovetail surfaces wear.
Define the term layout and briefly explain the purpose for layout. - The process of locating and marking a workpiece as a visual reference to guide machining operations.
What is the purpose of layout fluid (dye)? - To provide contrast and make it easier to see the layout lines.
Describe two safety precautions to observe when using layout dye. - review the SDS provided by the manufacturer for safety precautions. They will include working in an area with good ventilation, wearing safety glasses, and avoiding flame or ignition sources.
Briefly define a scriber and its use. - a sharp, fine point on one or both ends made of hardened steel or tungsten carbide, a tool used to mark straight layout lines that has a sharp
What two angles can be laid out with the combination square? - 45 degree angles, and the 45 degree side of the square head
What are three safety rules to observe when using screwdrivers? - use the correct type and size of screwdriver on each type of screw to avoid injury to yourself or damage to equipment. It is unsafe to carry screwdrivers in pockets or to use them around moving machinery.
List three types of screwdriver tips. - straight/slotted, phillips, torx
What is the advantage of using slip joint or tongue and groove pliers? - The slip joint enables the pliers to be adjusted in order to hold larger work. Pliers that have tongue-and-groove channels that enable the jaws to be adjusted to various sizes and held in place in the channel while the jaws are kept fairly parallel to each other.
What type of pliers have long jaws for holding small items and reaching in confined areas? - Needle nose
What is an advantage of using locking pliers? - so the user doesn’t need to continuously squeeze them by hand during use.
What type of saw uses a reciprocating (back and forth) cutting motion? - Power hacksaw
The vertical band saw is particularly useful, as it can be used to make straight cuts as well as ____________. - more complex contouring operations
The horizontal band saw is ideal for cutting ____________ ____________. - large pieces
List three safety precautions to observe when operating a horizontal band saw. - Never attempt to hold material by hand when using a horizontal band saw, and keep all body parts clear of the moving saw blade and any other moving machine parts. When moving long or heavy bars of material, get help to avoid injury, and always use proper lifting techniques.
Briefly describe the process to prepare for internal contour sawing on the vertical band saw. - it may be necessary to drill a hole in the inside of the boundary large enough to allow the blade to pass through.
What is the main benefit of offhand abrasive machining or grinding? - Abrasives can cut hardened steels that cannot be cut by other machining methods.
What type of metals should not be ground on a pedestal grinder with an aluminum oxide wheel? - Nonferrous metals
What abrasive machine is often used for light deburring of both ferrous and nonferrous metals? - Abrasive belt
What abrasive type wheel should be used to grind steel? - Aluminum oxide
What two abrasive type wheels are used to grind carbide tools? - Silicon carbide and diamond-impregnated
Define drilling. - The process of using a cylindrical rotating cutting tool that is sharpened on its end to create a hole.
What factors might determine when a hole must be finished by reaming? - To finishing an existing drilled hole to a precise size with a smooth finished surface
What are two reasons why a hole may need to be countersunk/chamfered? - so a flathead screw can be installed flush with the workpiece’s surface/ to deburr, allow easier entry of pins, or aid in starting threads in the hole.
Explain the purpose of a counterbore. - increases the diameter of a hole to a certain depth in order to allow a screw head or nut to be positioned flush with or below the workpiece surface.
What is the purpose of the pilot on a counterbore? - A guide on the end of a counterboring bit that keeps it aligned in the existing hole.
What are the two main materials used to make holemaking cutting tools? - high speed steel and tungsten carbide
What two types of shanks are commonly found on twist drills? - Straight-shank and tapered shanks
Name three functions of the flutes on a twist drill. ____________ ____________ ____________ - A patway for chips to flow out, a path for cutting fluid to flow into the hole and lubricate the cutting lips, also create the cutting lips.
What specific part of a twist drill point performs cutting? - The lips
What is the central point of a drill point that does not cut, but displaces material? - flutes
List five drill press safety guidelines. - Always wear safety glasses and observe all general shop safety rules when operating a drill press, Always remove drifts from drill press spindles immediately after use, Always remove keys from drill chucks immediately after loosening or tightening chucks, Always secure the workpiece before beginning any holemaking operation.
Briefly define the term cutting speed. - The distance that a point on the circumference of a rotating cutting tool travels in 1 minute
What unit of measure is used to define cutting speeds? - Surface feet per minute(SFPM)
What is the RPM formula that will be used throughout this textbook? Answer: -
What is feed - movement, or advancement, of the cutting tool into the workpiece
how is feed stated for drill press operations? - Inches per revolution or feed per revoluton
What are three benefits of precision grinding? - hold work securely and provide extremely precise movements of the grinding wheel to remove very small amounts of material, Precision grinding also has the ability to produce very fine surface finishes, Achieving tolerances of ±0.0001" is not unusual when operating a precision grinder.
What is the primary use of the surface grinder? - To produce flat surfaces.
What are the two spindle types used for surface grinders? - horizontal and vertical
What are the two types of table movements used for surface grinders? - eciprocating or rotary table motion
Label the parts of the surface grinder. -
What wheel shapes are commonly used for surface and cylindrical grinding? - Type 1 straight wheels
What three wheel shapes are often used for tool grinding? - Cup, saucer, and dish-shaped wheels
What abrasive is commonly used to grind steels? - aluminum oxide, ceramic aluminum oxide, or silicon carbide.
What abrasive is generally used to grind nonferrous metals, cast iron, and stainless steel? - Silicon carbide
The ability of individual grains to fracture and create new cutting edges is called ____________. - 8 to 600
List five surface grinder safety guidelines. - Never operate a grinder that is locked out or tagged out, and never remove another person’s lock or tag. Be sure that grinding wheels are sound before mounting and that all workpieces are secure before beginning any grinding. Do not force the wheel into the work. This could cause workholding devices to fail or grinding wheels to break. Always shut off the wheel and let it come to a complete stop before making workpiece adjustments or taking measurements. Do not reach around or beneath a grinding wheel while it is running.
What should be done to every grinding wheel before mounting? - check the maximum RPM listed on the blotter to make sure it is equal to or higher than the spindle RPM of the grinder.
What is the name of the paper discs used to cushion the force of the spindle nut when mounting a wheel? - blotter
Where is the best position to mount a diamond dresser on a magnetic chuck? - left edge
Should a diamond dresser be slightly offset to the left side or right side of the center of a wheel? - left side