Term
| What are 4 characteristics that cutting tools require? |
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Definition
| Cutting tools must be harder than the metal they are cutting, tough enough to withstand stresses and shocks associated with machining, they must be able to withstand the intense heat generated when metal is being cut(Red Hardness) and they must be wear-resistant. |
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Term
| What are 3 key advantages of HSS Tools? |
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Definition
-It is tougher than any other cutting material, making it ideal for drills, reamers, end-mills and taps.
-It is inexpensive.
-It can be shaped and sharpened easily using common grinding wheels |
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Term
| What are 3 disadvantages of HSS Tools? |
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Definition
-It is not as hard or wear-resistant as other cutting materials and must be sharpened regularly.
-It does not stand up to heat that well and generally requires the use of coolant
-It has the lowest cutting speed of any modern cutting materials. |
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Term
| How much higher of a cutting speed is carbide in comparison to HSS. |
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Definition
| Carbide can generally be run 8 times faster than HSS tools. |
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Term
| What are 3 main advantages of carbide tools? |
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Definition
-It retains its hardness even at temperatures of 1400 degrees F allowing cutting speeds 8 times higher than HSS.
-It is harder and more wear-resistant than HSS.
-It can be used with or without coolant (NEVER BOTH) |
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Term
| What are 3 main disadvantages of carbide tools? |
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Definition
-They are not as tough as HSS
-It is more expensive than HSS
-It is not easily shaped or sharpened |
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Term
| What is the benefit of a coated carbide insert? |
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Definition
| The coating increases the wear resistance of the insert allowing more use out of the tool before it needs to be indexed. |
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Term
| Why would you choose to use CBN tooling over diamond tooling? |
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Definition
| You would choose CBN over diamond when cutting ferrous metals as diamond will have a chemical reaction with the ferrous metal causing the diamond to break down. |
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Term
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Definition
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Term
| Where are relief(clearance) angles ground on a tool? |
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Definition
| They are ground beneath the cutting edges. |
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Term
| Where are rake angles ground on a tool? |
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Definition
| They are ground on the face of the tool |
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Term
| What is the purpose of a side cutting edge angle? How does it affect the chips? |
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Definition
| A side cutting edge protects the nose of your tool, it makes the chip longer and thinner. |
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Term
| What would be the purpose of a low end cutting edge angle? A high end cutting edge angle? |
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Definition
| A low end cutting edge angle would make your tool stronger and good for roughing cuts. A high end cutting edge angle is good for finishing cuts but it weakens the nose of your tool. |
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Term
| What is the purpose of a side relief(clearance) angle? What changes as this angle becomes larger? |
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Definition
| The purpose of the side relief(clearance angle is to allow the tool to advance along the work without rubbing. The larger the angle the faster you can cut into your material(feed rate) but it also makes your tool weaker as this angle increases. |
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Term
| What does a side rake angle determine? |
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Definition
| The side rake angle on a tool determines the shape of the chip and the direction of the chip flow. |
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Term
| What is the difference between a negative and positive side rake angle? |
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Definition
| A positive rake reduces friction and heat and allows the chip to flow more effectively. Negative rakes make the tool stronger because there is more support under the cutting edge. |
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Term
| What is the purpose of a nose radius? What is the standard nose radius size? |
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Definition
| A nose radius increases the strength of the cutting tool increasing its tool life and allowing higher feed rates. The standard nose radius is 1/16" |
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Term
| What is the difference between constant RPM and constant surface speed? |
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Definition
| Constant rpm means your rotations of your spindle will be consistent. Constant surface speed means the amount of material contacting your tool is always the same as you are facing a part. This is only possible in C.N.C. lathes. |
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Term
| What amount of material should be left on your last roughing cut to leave enough material for finishing. |
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Definition
| You should leave approx. 0.050" to 0.030" for finishing. |
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Term
Ceramic cutting tools:
a) are available only as a brazed on tool
b) require a chip breaker to cut effectively
c) require coolant
d) require a very rigid set-up |
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Definition
| d)Ceramic cutting tools require a very rigid set-up |
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