Card Set Information

2013-01-15 20:30:14

Show Answers:

  1. Rule of Thumb for runout
    Runout must be minimum <0.025mm
  2. Cutting Speed of carbide? Compared to steel.
    3 x cutting speed of HSS
  3. Why are carbide drills self-centering? 
    No chisel edge. Starts cutting right at the tip. 
  4. Angles of Carbide Drills? 
    135, 138, 140.
  5. Angles of HSS drills. 
  6. Rule of Thumb for drill (2 flute twist drills)
    0.001"(1 thou) FpR for every 1mm diameter of drill. 
  7. Rule of Thumb for exiting into an uneven surface
    Reduce feedrate to 30%. 
  8.    Pecking
    3 times diameter depth for each peck.
  9. HSS Twist Drills
    Low Cost/Lower cutting speeds/tough but not hard/use in lower rpm machines/around 90 sfm for steel
  10. Carbide tip drills
    cheaper than solid carbide/tips can break off/can run at higher speeds than HSS due to hardness
  11. Solid Carbide Drills
    Expensive/Hard but not tough/For smaller diameters and holes with tighter tolerances. 
  12. Pilot Drill
    Stubby length/ Provides an accurately positioned pilot hole for gundrills or other deephole drills.
  13. Replaceable Tip Drills
    Expensive/Higher chiploads than indexable style drills/ coolant thru/ two effective flutes
  14. Indexable Drills
    Higher speed/ Lower Feed/ One Flute effective/ faster toolchanges
  15. Drilling Theory for Indexable Drills- Cutting Speed
    Cutting speeds for indexable drills declines from 100% at the outside to 0% in the center. 
  16. Stepdrills
    Less tools required/Reduces cycle time/Adds chamfers or counterbores/can produce multiple diameters with one tool
  17. Sefas and BF Bodies
    Can do chamfers or spot faces/eliminates need for separate chamfer tool/eliminates need for stepdrill/replaceable inserts are expensive/possible runout problem if setup in endmill holder
  18. Spade Drills
    reduced downtime due to tool changes/ for deeper holes/ for cored holes/ body holds various sizes of insert/ lower cutting speeds than indexable style 
  19. Combination Tools
    drill and chamfer
  20. G- Drills 
    For Aluminum or Cast iron/ 4 Guiding margins/ works well for deep drilling/ requires coolant thru
  21. 3 flute drill
    better stability/ good on cored holes/ higher feedrates due to more flutes/ good for breaking out into uneven surfaces/ good for only free chipping materials (iron)
  22. Coredrills
    Opening previously cored holes/ Not centre cutting/ 2 effective flutes/ Can have good feedrates/ Generally Specially made
  23. Centredrills
    For drilling centres for tailstocks/ Bell type centredrill has a seperate 120 degree angle to protect the 60 degree angle
  24. Spotdrill
    short and rigid/ creates accurate starting spot for drills to maintain true position/must have smaller tip angle than drills/usually 90 or 120 degrees/ chamfering existing holes
  25. Flat bottom drill
    not an endmill/creates flat bottom holes/ pilot holes/ speed and feed alot faster than endmill/ creates a starting flat for drills on an angled surface
  26. Aluminum
    greatly reduces exit burrs/self centering/good on cored holes
  27. port cutter
    universal standards for hose fittings/ predrilled first/ complex geometries with spotfaces
  28. spot facing tools
    used for spotfacing an existing hole/ not centre cutting
  29. Deep Hole Drilling
    with guide pads/ requites good coolant volume and pressure
  30. Gundrills
    for straight deep holes/high RPM, low chipload/used with high pressure coolant or oil/hollow body/must be used with pilot hole or bushing/regrindable
  31. Parabolic flute drill
    deep hole drilling/ helps chip evacuation/ commonly used in aluminum/slow helix
  32. High helix drill
    good surface finish/fast helix/creates less radial force
  33. Double margin drill
    for good reamer like surface finish/ burnishing effect/ more stability when drill in bushing/ for interrupted cuts or uneven breakouts
  34. Form Drill
    custom shapes/eliminates many tools/complex profiles/expensive
  35. What is the largest factor determining tool life?
  36. What size should a predrilled hole be/
    smaller, only 25% of the drill diameter to avoid drill deflection