Drills

Runout must be minimum <0.025mm

3 x cutting speed of HSS

No chisel edge. Starts cutting right at the tip. 

135, 138, 140.

118.

0.001"(1 thou) FpR for every 1mm diameter of drill. 

Reduce feedrate to 30%. 

3 times diameter depth for each peck.

Low Cost/Lower cutting speeds/tough but not hard/use in lower rpm machines/around 90 sfm for steel

cheaper than solid carbide/tips can break off/can run at higher speeds than HSS due to hardness

Expensive/Hard but not tough/For smaller diameters and holes with tighter tolerances. 

Stubby length/ Provides an accurately positioned pilot hole for gundrills or other deephole drills.

Expensive/Higher chiploads than indexable style drills/ coolant thru/ two effective flutes

Higher speed/ Lower Feed/ One Flute effective/ faster toolchanges

Cutting speeds for indexable drills declines from 100% at the outside to 0% in the center. 

Less tools required/Reduces cycle time/Adds chamfers or counterbores/can produce multiple diameters with one tool

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

reduced downtime due to tool changes/ for deeper holes/ for cored holes/ body holds various sizes of insert/ lower cutting speeds than indexable style 

drill and chamfer

For Aluminum or Cast iron/ 4 Guiding margins/ works well for deep drilling/ requires coolant thru

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)

Opening previously cored holes/ Not centre cutting/ 2 effective flutes/ Can have good feedrates/ Generally Specially made

For drilling centres for tailstocks/ Bell type centredrill has a seperate 120 degree angle to protect the 60 degree angle

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

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

greatly reduces exit burrs/self centering/good on cored holes

universal standards for hose fittings/ predrilled first/ complex geometries with spotfaces

used for spotfacing an existing hole/ not centre cutting

with guide pads/ requites good coolant volume and pressure

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

deep hole drilling/ helps chip evacuation/ commonly used in aluminum/slow helix

good surface finish/fast helix/creates less radial force

for good reamer like surface finish/ burnishing effect/ more stability when drill in bushing/ for interrupted cuts or uneven breakouts

custom shapes/eliminates many tools/complex profiles/expensive

Speed

smaller, only 25% of the drill diameter to avoid drill deflection