Scribd
Upload
62 views1 page

Drilling PDF

This document provides common formulas used in drilling operations. It includes formulas to calculate: 1) RPM based on cutting speed (vc) and drill diameter (D). 2) Cutting speed based on RPM and drill diameter. 3) Material removal rate based on feed rate (vf), cross-sectional area of the hole (AT), and depth of hole (L). 4) Power requirement based on drill diameter, feed rate, cutting speed, and specific cutting force (kc).

Uploaded by

Bang JOJON
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF, TXT or read online on Scribd
62 views1 page

Drilling PDF

This document provides common formulas used in drilling operations. It includes formulas to calculate: 1) RPM based on cutting speed (vc) and drill diameter (D). 2) Cutting speed based on RPM and drill diameter. 3) Material removal rate based on feed rate (vf), cross-sectional area of the hole (AT), and depth of hole (L). 4) Power requirement based on drill diameter, feed rate, cutting speed, and specific cutting force (kc).

Uploaded by

Bang JOJON
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF, TXT or read online on Scribd
You are on page 1/ 1

Common Drilling Formulas

RPM = vc x 12
3.14 x D
RPM (rev/minute)
or RPM = (3.8197 / D) x SFM

vc = RPM x 3.14 x D
Cutting 12
(ft/min)
Speed
or SFM = 0.2618 x D x RPM

Feed f = Feed per revolution (IPR) (inch/rev)


vf = IPR x RPM (inch/min)
Rate
h = Distance from drill point to workpiece
Cross-section before feeding (inch)
AT = 3.14 x R2 (in2)
area of hole
kc = Specific cutting force (Lbf/inch2)

Material L = Depth of hole (inch)


Q = vf x AT (inch3/min)
Removal Rate
ɳ = Machine efficiency (%)

Power Pc = D/4 x f x vc x kc (Hp)


D = Tool diameter (inch)
Requirement 33,000 x ɳ

Torque Mc = Hp x 5252 (ft/lbs)


RPM

Feed
Ff = .7 x D/2 x f x kc (lbs)
Force (approx.)

Tc = L + H (Min/piece)
vf
Machining
Time
or Tc (seconds) = (60 x feed minus stroke)
IPM

You might also like