1. Drilling Operations
Mr. Casper

2. Objective
Students will be able to identify different tooling used in drilling process.
Students will be able to safely operate a power drill, drill press, and vertical mill.

3. Unit Outline Punching & Piloting Tooling Drilling Machines
Twist Drills
Whole Saw
End Mills
Drilling Machines
Power Drill
Drill Press
Mill
Lathe
Drilling Procedure
Safety

4. Tooling
Drill bits are cutting tools used to create cylindrical holes, almost always of circular cross-section.
Bits are held in a tool called a drill, which rotates them and provides torque and axial force to create the hole.
Specialized bits are also available for non-cylindrical-shaped holes.

5. Pilot Holes
A pilot hole is a smaller hole drilled into a material prior to a larger hole being drilled
Pre-Drilling is a must on smooth metal
Large bits will slip and wonder
potential safety hazard
Good chance you will damage your piece

6. Pilot Hole Procedure 1. Mark with a center punch
2. Drill the pilot hole
3. Drill hole to finished diameter
4. Clean up

7. Twist Drills The most common type of drill bit
Can be used for wood, metal, plastic, and other material.
The geometry and sharpening of the cutting edges is crucial to the performance of the bit.
118* point angle is standard but may vary
(90*plastic vs. 150* steel)

8. Drill Bit Geometry

9. Sharpening Twist Drills
Three essential characteristics 1. Equal drill point angle 2. Equal cutting edge/lips 3. Clearance behind lips KEEP THE BIT COOL!

10. 1. Equal Drill Point Angles
118* is standard

11. 2. Equal Cutting Edge/Lips
A handyman's adjustable protractor can be used to check both the drill-point angle and the lengths of the cutting edge lips.

12. 3. Clearance Behind Lips Visually inspect clearance to 8-12 degrees.
Not super critical as long as it’s close.
Too Little prevents the cutting edge from producing a chip and the bit will not drill.
Too much clearance weakens the cutting edge because too much metal behind the edge is removed.

13. Sharpening Video

14. Drill Bit Chemistry Used for wood Require frequent sharpening
Low Carbon Steel Bits
Used for wood
Require frequent sharpening
Can dull from drilling some hardwoods.
High Carbon Steel Bits
Used for wood and mild steel
Less frequent sharpening
High Speed Steel (HSS)
Greater durability than carbon
Most common
Replaced most carbon bits

15. Drill Bit Chemistry Cobalt Used for stainless steels
HSS bit that contains more cobalt
Hold hardness at much higher temperatures
Tungsten Carbide
Extremely hard & can drill through almost any material
Expensive to manufacture, usually the tungsten is brazed onto the tips.
Polycrystalline diamond (PCD)
Hardest of all tool materials
Extremely Resistant to wear
Commonly used for glass and tile
Thin layer (0.02”) of diamond is brazed onto the cutting edge.

16. Hole Saws
The saw consists of a steel cylinder usually mounted on an arbor.
Teeth are commonly made from steel, some are diamond tipped.
The arbor holds a drill bit which helps centering the bit.

17. Hole Saw Advantages Efficiency Size
Little of the total material being removed is actually cut, which ultimately reduces the overall power requirement.
Size
Cheaper tooling is required for drilling large holes.

18. Hole Saw Disadvantages
Drilling machine being used must produce lots of torque at low speeds.
VERY powerful kickback. Attach side handles to drills.
Difficult removal of material from core.

19. End Mills
END MILLS ARE NOT DRILL BITS!!!

20. End Mills
While a drill bit can only cut in the axial direction, a milling bit can generally cut in all directions.
End mills are used in milling applications such as profile milling, tracer milling, face milling, and plunging.

21. CNC Milling Video

22. Flat End Mills | Ball End Mills

23. T-Slot Mill Shell Mill

24. Countersink
Performed by using either a countersink or larger dill bit.
Required for flat or recessed surfaces.
Characterized by tapered underside.
Pilot hole is required.

25. Counterbore Performed by plunging a flat end mill
Required for flat or recessed surfaces
Characterized by flat underside

26. Reaming
A reamer enters the work piece axially and enlarges an existing hole to the diameter of the tool.
A reamer is a multi-point tool that has many flutes, which may be straight or in a helix.
Removes minimal material.
Often performed after drilling for a smoother finish.

27. Tapping
A tap enters the workpiece axially and cuts internal threads into an existing hole specifically designed for the tap.
The tap is selected based on the major diameter and pitch of the threaded hole.
Threads may be cut to a specified depth inside the hole (bottom tap) or the complete depth of a through hole (through tap).

28. Drilling Machines
Drill
Drill Press
Milling Machines
Lathes

29. Power Drills Use corded drills for long drill cycles
Caution: Drill may catch & twist near the end of the drill cycle.
Don’t lose the chuck key!

30. Drill Press

31. Mill & Lathe Used when extreme accuracy is needed.
Ideal for deep drilling operations.

32. Drilling Procedure Use a punch to mark your hole.
Tighten bit in ALL locations.
Measure bit diameter for precise drilling before drilling!
Use cutting fluid during operation
Cleanup and de-bur holes with a file or countersink tool

33. Drilling Safety
Do not hold material with your hand, use a vice or clamp.
PPE: Safety glasses, no lose clothing, tie hair back, no gloves
Stand balanced & never lean toward the machine
Make sure the chuck is secure in the shank.
Never leave a chuck key in the chuck socket!
Line up and set depth BEFORE drilling.
Use sharp bits.
Adjust speed when the machine is ON!
Larger bits = slow RPM
Small bits = faster RPM

34. Drilling Safety Cont.
If your piece spins remain calm and shut the machine off.
Reduce feed rate near the end.
Keep the bed clean, remove scraps, use a brush!
Remove your bits when your finished!
Put the chuck key back into the bed!

35. Cutting Fluids Characteristics
Cools
keeps the work piece at a stable temperature
critical when working to close tolerances
Very warm is OK
Avoid rapid heating and cooling (warping)
Maximizes tool life
Lubricates & Removes chips
Small pieces can weld themselves onto the tooling if they become too hot.
Prevents Rust
Machine Parts & Tooling

36. Types of Fluids Mineral Synthetic & Semi-Synthetic Water
Petroleum Based
Vary from dark heavy oils to light clear oils.
Synthetic & Semi-Synthetic
Combination of the best properties of oil and water
Rust inhibition
Compatibility: ability to work with different metals
Thermal breakdown
Environmental safety
Water
Pros: Good Conductor of heat
Cons: Poor Lubrication & Corrosion

37. Pastes or Gels Similar to lipstick or beeswax. Popular for Band Saws
Periodically apply to the blade
Hand Operations
Drilling
Cutting threads