Schließen
Name three materials used to manufacture drills and state the advantage of any two.
Define the body, web, and point of a twist drill.
State the purpose of this part: Tang
State the purpose of: Flutes
State the purpose of: Margin
State the purpose of: Body clearance
Why are various drill points and clearances used for drilling operations?
Describe and state the purpose of the following drill points:
Conventional
Describe and state the purpose of the following drill points:
long angle
Describe and state the purpose of the following drill points:: flat angle
Why is it necessary to thin the web of a drill?
List four systems of drill sizes and give the range of each.
State the purpose of the high-helix drill
State the purpose of the Core drill
State the purpose of the Oil hole drill?
State the purpose of the Straight-fluted drill
State the purpose of the gun drill.
State the purpose of the hard-steel drill
What problems generally result from the use excessive speed and excessive feed?
Discuss excessive lip clearance and insufficient lip clearance.
What is the effect of drills with unequal angles on the cutting lips?
What is the effect of drills with cutting lips unequal length?
What are the characteristics of a properly ground drill?
Unit 41: Why is it important that a drill be operated at the correct speed?
explain the difference between cutting speed and r/min.
What factors determine the most economical drilling speed?
Calculate the r/min required to drill the following holes using a high-speed drill:
A 3/8 in diameter hole in tool steel
Calculate the r/min required to drill the following holes using a high-speed drill: A 1-inch diameter hole in aluminium
Calculate the r/min required to drill the following holes using a high-speed drill:
a 9 mm hole in steel casing
Calculate the r/min required to drill the following holes using a high-speed drill:
a 20 mm hole in cast iron
What is the purpose of a cutting fluid
Name four important qualities that a cutting fluid should have?
Select three of the most important safety suggestions and explain why they should be observed?
What result might be expected from too high a drill speed?
What results might be expected from too low a drill speed?
Why is it good practise to start each hole with a center drill?
State three reasons a center drill should be removed from the work frequently.
Why should center holes not be drilled too shallow?
Why should center holes not be drilled too deep?
What is the purpose of spotting a hole before drilling?
How deep should each hole be spotted?
What is the purpose of fastening a clamp or table stop to the left side of the drill press table?
When should drilling pressure be eased?
List the procedure for laying out a hole before drilling to a layout?
How deep should the hole be drilled before the drill point indentation is examined?
Explain how a drill may be drawn over to a layout.
List three disadvantages of a thick web found on large drills.
What are pilot holes and why are they necessary?
Why should pilot holes not be drilled any larger than necessary?
How high should the drill press table be adjusted when drilling large holes?
