Term
| What are 7 Positive Qualities of a Granite Surface Plate? |
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Definition
A granite surface plate has these qualities:
-It will not distort since it is a natural material aged over millions of years.
-It is non-magnetic. Cast iron surface plates however can become magnetic over time.
-It does not rust.
-It does not burr; however it may chip.
-It may be used near grinding machines because abrasive particles will not embed in the plate.
-It is typically cheaper than a cast-iron plate. |
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Term
| What are some ways to care for a surface plate? |
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Definition
Some ways to care for a surface plate are:
- Do not hammer or punch on the surface plate
-Always keep the surface plate covered when not in use
-Keep the surface plate clean at all times, in the case of cast iron light oil will keep it in good condition.
-Protect the surface of the plate by placing the work on parallels instead of directly on the plate.
-Place workpieces and gauges carefully on the plate. Never drop the workpiece.
-Remove burrs and protrusions from cast iron plates with a honing stone. |
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Term
| What is the purpose of dividers and trammels? Why would you want to use a trammel instead of a divider? |
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Definition
| Dividers and trammels are used to scribe arcs and circles and for transferring measurement. Dividers are best for smaller diameter circles while trammels can make much larger arcs and circles when needed. |
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Term
| What is a hermaphrodite caliper used for? |
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Definition
| A hermaphrodite caliper is typically used to scribe lines parallel to an edge. You can also use it to locate the centre on the end of round stock. |
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Term
| What is the included angle of a prick punch? What is it's purpose? |
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Definition
| A prick punch has an included angle of 30 to 60 degrees. It's purpose is to make it easier to pick up the lines that have been scribed and their intersections before centre punching the workpiece. |
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Term
| What is the included angle of a centre punch? What is it's purpose? |
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Definition
| The included angle of the point of a centre punch is 90 degrees. It's purpose is to leave wide indentations on the surface of the workpiece known as permanent layout or witness marks. This way even if the layout die is wiped away |
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Term
| How would you use a angle plate with a toolmakers clamp to scribe two lines at 90 degrees? |
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Definition
| You would first scribe the first line, then flip the angle plate on it's side and adjust the tool makers clamp(s) if need be. then scribe the second line. Be sure not to compromise your accuracy by moving your workpiece. |
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Term
| How should a tool makers clamp be adjusted? |
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Definition
| To adjust a tool makers clamp turn the screws until both jaws are parallell to the width of the workpiece, then tighten the rear screw to clamp the workpiece into position. |
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Term
A tool maker's clamp is:
a) used for clamping for milling and turning operations
b) used for heavy-duty clamping
c) another name for a C-clamp
d) used for light clamping operations |
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Definition
| d) A tool maker's clamp is used for light clamping operations |
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Term
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Definition
| A datum edge is a flat surface that serves as a starting point when making measurements? |
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Term
| What is incremental dimensioning/chain dimensioning? |
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Definition
| It is a dimensioning method that starts the next dimension based on the end of the last dimension. It's a very compact dimensioning system but it has the large disadvantage of allowing tolerances to accumulate. Whenever possible approach chain dimensioning as though it was absolute dimensioning. |
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Term
| What is Absolute/Datum/Baseline dimensioning? |
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Definition
| It is a dimensioning system that makes all dimensions measured from the original datum line thus preventing accumulation of error and avoiding major tolerance variation. |
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Term
| When picking which layout die to use on a workpiece what is a major precaution you must take with Copper Sulfate layout dye? |
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Definition
| Copper sulfate layout die is acidic thus it should only be applied to ferrous metals because it will react with non-ferrous metals. |
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Term
Copper Sulfate layout solution should be used on:
a) ferrous metals
b) metals containing copper alloys
c) aluminum
d) all non-ferrous metals |
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Definition
| a) Copper Sulfate layout solution should be used on ferrous metals. |
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Term
The surface gauge is used:
a) to layout lines perpendicular to an edge
b) as a direct measuring instrument
c) to layout lines parallel to the edge of a workpiece
d) for percise measurement |
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Definition
| c) The surface gauge is used to layout lines parallel to the edge of a workpiece. |
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Term
Trammels are used for scribing when:
a) all circles to be scribed are larger than 6 inch in diameter
b) the circle to be scribed is beyond the range of the dividers
c) dividers are not obtainable
d) greater accuracy is required |
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Definition
| b) Trammels are used for scribing when the circle to be scribed is beyond the range of the dividers |
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Term
| What are the different grades of a surface plate? |
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Definition
The different grades of surface plate are:
AA Grade - Labratory
A Grade - Inspection
B Grade - Workshop |
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