Dimensioning Twist Drills
Dimensioning Twist Drills
(OP)
We are designing a custom drill for orthopedic use and need to dimension the flutes and the tip including the web, land, chisel edge, etc.
ASME B94.11M-1993 does not show helix angles, web thickness dimensions and the like; nor does the Machinery's Handbook.
Does anyone have an example of an accepted method for dimensioning (custom) twist drills?
Thanks in advance,
Pberg
ASME B94.11M-1993 does not show helix angles, web thickness dimensions and the like; nor does the Machinery's Handbook.
Does anyone have an example of an accepted method for dimensioning (custom) twist drills?
Thanks in advance,
Pberg





RE: Dimensioning Twist Drills
RE: Dimensioning Twist Drills
RE: Dimensioning Twist Drills
That is a new one. Too expensive.
The tip automatically gets larger
as it heats up.
RE: Dimensioning Twist Drills
diamondjim
Get a drill and a micrometer, check the land diameter close to the cutting edge and then close to the shank. You will see the taper.
RE: Dimensioning Twist Drills
RE: Dimensioning Twist Drills
Thanks for the url on the twist drills.
My apology for not picking up this new
technology. We have been coating the
drills for years, but have never seen
this back taper. I have relayed this to
the shop guys to check this out.
Drilling and grinding has been our
greatest hindrance in getting parts
thru the shop on time.
RE: Dimensioning Twist Drills
If your guys are watching the drills and patiently picking off bird nests of long stringy chips, they may be doing it wrong, or using the wrong drills. Of course it depends on what you're drilling, but in readily machinable materials, a drill should spit out small, hot, fragmented chips, so fast that it can't clog.
Sometimes increasing feed or speed or both is all that's necessary. Sometimes premium or special drills are required to make that possible. Even experienced machinists usually run drills too slow and with too little feed, especially small drills, "so they don't wear out".
Hint: Drill bits are consumables. If you're not buying them on a regular basis, you could probably run them harder and save money and increase production, even if you have to buy the most expensive ones.
Mike Halloran
Pembroke Pines, FL, USA
RE: Dimensioning Twist Drills
RE: Dimensioning Twist Drills
I do not think the shop can be accused
of drilling too slow. We drill either
alloy steels or aluminum.
English Muffin,
I guess we never measured any drills
before to check out back taper.
Thanks for the info.
RE: Dimensioning Twist Drills