N - Marking Out and Broaching Flashcards
First step in “Marking Out” the hole placement when drilling manually
Marking Blue
Used to scratch a cross at the desired location to drill manually
SCRIBER
Parts of a SCRIBER
Bent point
Straight Point
Grip
Used to create a small “Center Pot” or indentation at the center of the scratched cross
CENTER PUNCH (hammered or automatic hammerless type)
Short and stubby cutting tool which makes a shallow conical hole at the precise location that acts as a “funnel” for the subsequent twist drill. It has a small starter point to stop the “dancing”, which is immediately followed by a tapered shoulder.
CENTER DRILL
Twist drill which is 1/32’’ smaller than the desired hole used to remove the bulk of the metal, leaving a rather rough bore to the hole.
PILOT DRILL
Standard twist drill which completes the drilling procedure with the desired final diameter of the hole.
FINISH DRILL
CNC drilling requires _ tools to complete a task and _ automatic tool changes
3, 2
All steps in CNC Drilling
CENTER DRILL - PILOT DRILL - FINISH DRILL
ALSO: COUNTERSINK, COUNTERBORING, REAMING, TAPPING
Accommodations made to final finished holes for screw heads
HOLE MODIFICATION
When the hole is to carry a FLAT HEAD SCREW it must be modified to sit flush with the surface
COUNTERSINKING (60 DEGREES)
When the hole is to carry a CAP SCREW it must be modified to sit flush with the surface
COUNTERBORING
TRUE OR FALSE:
An oversized twist drill is NOT generally used for counterboring since this would not produce a flat seat to the counterbore
TRUE
A metal cup with serrated teeth along the periphery and a pilot twist drill in the center for proper positioning
HOLE SAW
Preferred way of cutting large holes in metal plate. Cannot be used in a power tool as they need to be held rigidly. Uses SPCT or “inserts”
TREPANNING TOOL
Tools not capable of cutting “Blind Holes”
TREPANNING TOOL
HOLE SAWS
Hole modification to make a drilled hole very smooth and with precise dimensions.
REAMING (performed using a REAMER)
Hole in which REAMING is performed
FINSIH DRILLED HOLE
(MUST BE 1/64TH UNDERSIZED)
Most common MACHINE TOOLS dedicated to hole making operations
VERTICAL DRILL PRESS
(also known as:
STAND DRILL
VERTICAL DRILL
DRILL PRESS
SENSITIVE DRILL)
Large, heavy duty machine capable of drilling big diameter holes while providing precise motion of the drill head with multiple degrees of freedom
RADIAL ARM DRILL
Various cutting tools are sequentially placed into the JACOB’S CHUCKS, and are simply rotated to bring each desired tool to the lower position aligned above the hole.
TURRET DRILL
(TURRET/CAPSTAN)
Lining up of several drill presses in a row
MULTIPLE SPINDLE DRILLING MACHINES/ GANG DRILLING
Custom made attachments for specific applications, usually driven by the single spindle of a Stand Drill or Radial Arm.
MULTI SPINDLE DRILL HEAD ATTACHMENTS
A single point cutting tool on the end of a long rod
BORING BAR
Another way of making a large hole. A smaller hole is predrilled, then a bar is used to remove material from the walls, thereby opening up the diameter
BORING
One of the earliest machines that could cut non round shapes. Only capable of cutting flat surfaces. Used to reduce the thickness of bar stock, cut straight grooves, or produce linear steps.
SHAPING MACHINE/SHAPER
Operations performed on a SHAPER
Horizontal Cutting
Vertical Cutting
Inclined Cutting
Irregular Cutting
“Big Brother” of the SHAPER, which can make huge cuts of metal. Keeps the cutting tools stationary and brings the material to them.
PLANING MACHINE/PLANER
Linear cutting process that uses a long and slender tool which is slightly tapered.
BROACHING
One of the most common broaching operations
Creation of KEYWAYS in shaft hubs
Rectangular BROACH with teeth only along one side
KEYWAY BROACH
OAL
Overall Length
Placed in the hole to guide the broach as it is pushed through
Collared Keyway Bushing
Used after each stroke in BROACHING to create deeper cuts
Keyway Broach Shims
Type of broaching where both the cutter and the workpiece rotate at the SAME speed in the SAME direction.
ROTARY BROACHING
what is the wobble angle in broaching?
1 degree
Rotary Broaches can also be used in a
DRILL PRESS/ MILL with a stationary workpiece
Short, stubby cutters that have the required cross-sectional geometry and a large degree angle. Cutters capable of creating blind, polygonal holes in a workpiece.
ROTARY BROACHING BITS
