A30-TAS_US-EN

DRILLING | T-A® Replaceable Insert Drilling System

Tap Drill InformaƟon and Formulas | Imperial (inch)

A

American - Unified Inch Screw Thread

Formulas 1. RPM = (3.82 • SFM) / DIA where: RPM

Probable Mean Oversize

DRILLING

Tap Drill Size

Decimal Equivalent

* Theo % Thread

Probable Hole Size 0.3890" 0.3936" 0.4164" 0.4249" 0.4405" 0.4561" 0.4718" 0.4874" 0.4754" 0.5030" 0.5148" 0.5186" 0.5343" 0.5499" 0.5655" 0.5739" 0.5811" 0.6124" 0.6436" 0.6526" 0.6593" 0.6749" 0.6905" 0.6920" 0.7686" 0.7843" 0.7999" 0.8155" 0.8624" 0.8936" 0.8691" 0.8780" 0.8936" 0.9093" 0.9249" 0.9405" 1.0343" 1.0499" 1.1124" 0.8780" 0.9403"

** Probable % Thread

Tap Size 7/16 - 20

= revoluƟons per minute (rev/min)

W 0.3860

79% 72% 87% 78% 63% 72% 87% 72% 83% 87% 70% 65% 79% 72% 87% 75% 65% 72% 84% 77% 72% 72% 77% 75% 76% 65% 84% 67% 72% 72% 82% 77% 67% 87% 72% 67% 87% 72% 76% 68% 77%

0.003" 0.003" 0.003" 0.003" 0.003" 0.003" 0.003" 0.003" 0.003" 0.003" 0.003" 0.003" 0.003" 0.003" 0.003" 0.003" 0.003" 0.003" 0.003" 0.003" 0.003" 0.003" 0.003" 0.003" 0.003" 0.003" 0.003" 0.003" 0.003" 0.003" 0.003" 0.003" 0.003" 0.003" 0.003" 0.003" 0.003" 0.003" 0.003" 0.003" 0.003"

75% 68% 84% 75% 60% 68% 84% 69% 80% 82% 66% 61% 77% 69% 82% 75% 70% 69% 82% 75% 70% 69% 73% 71% 74% 63% 81% 64% 69% 68% 81% 75% 65% 84% 69% 64% 84% 69% 74% 65% 75%

SFM

= speed (Ō/min)

7/16 - 20 25/64"

0.3906

DIA

= diameter of drill (inch)

1/2 - 13 10.5 mm 0.4134

1/2 - 13 1/2 - 13 1/2 - 20

27/64"

0.4219 0.4375 0.4531 0.4688 0.4844 0.5000" 0.5156" 0.5313" 0.5469" 0.5625" 0.5781" 0.6094" 0.6406" 0.6563" 0.6719" 0.6875" 0.7656" 0.7813" 0.7969" 0.8125" 0.8594" 0.8906" 0.8750" 0.8906" 0.9063" 0.9219" 0.9375" 1.0313" 1.0469" 1.1094" 0.8750"

2. IPM = RPM • IPR where: IPM = inches per minute (in/min) RPM

7/16"

29/64"

9/16 - 12 15/32"

B

= revoluƟons per minute (rev/min)

9/16 - 12 12.0 mm 0.4724

IPR

= feed rate (in/rev)

9/16 - 12 31/64"

9/16 - 18

1/2"

3. SFM = RPM • 0.262 • DIA where: SFM = speed (Ō/min) RPM

BORING

9/16 - 18 13.0 mm 0.5118"

9/16 - 18 31/64"

5/8 - 11 5/8 - 12 5/8 - 18

17/32" 35/64"

= revoluƟons per minute (rev/min)

DIA

= diameter of drill (inch)

9/16"

5/8 - 18 14.5 mm 0.5709"

5/8 - 18

37/64"

4. Thrust

= 153,700 • IPR • DIA • K m

11/16 - 12 39/64"

where: Thrust

3/4 - 10

41/64"

= axial thrust (lbs) = feed rate (in/rev)

C

3/4 - 10 16.5 mm 0.6496"

IPR DIA

3/4 - 10 3/4 - 12 3/4 - 16 7/8 - 9 7/8 - 9 7/8 - 14 7/8 - 14

21/32" 43/64" 11/16" 49/64" 25/32" 51/64" 13/16"

= diameter of drill (inch)

K m

= specific cuƫng energy (lbs/in 2 )

REAMING

3/4 - 16 17.5 mm 0.6890"

5. Tool Power = .6283 • IPR • RPM • K m • DIA 2 where: Tool Power = tool power (HP) IPR = feed rate (in/rev) RPM = revoluƟons per minute (rev/min) K m = specific cuƫng energy (lbs/in 2 ) DIA = diameter of drill (inch)

15/16 - 12 55/64" 15/16 - 20 57/64"

1 - 8 1 - 8 1 - 8

22.0 mm 0.8661"

7/8"

D

57/64" 29/32" 59/64" 15/16"

1 - 12 1 - 12 1 - 14

Material Constants

BURNISHING

K m (lbs/in 2 )

1-1/8 - 12 1-1/32" 1-1/8 - 12 1-3/64" 1-1/4 - 7 1-7/64"

Type of Material

Hardness

Plain Carbon and Alloy

85 - 200 BHN 0.79 200 - 275 BHN 0.94 275 - 375 BHN 1.00 375 - 425 BHN 1.15 135 - 275 BHN 0.94 30 - 45 RC 1.08 100 - 200 BHN 0.50 200 - 300 BHN 1.08 - 1.44

24 x 2 27 x 3

7/8"

Steel

24.0 mm 0.9449"

Taper Pipe Thread (NPT)

High-Temperature Alloys

Probable Mean Oversize

Stainless Steels

E

Tap Drill Size

Decimal Equivalent

Theo % Thread*

Probable Hole Size

Probable % Thread**

Tap Size 1/4 - 18 3/8 - 18 1/2 - 14 3/4 - 14

Cast Iron

7/16 9/16

0.4375 0.5625 0.7031 0.9063

- - - -

0.003 0.003 0.003 0.003

0.4405 0.5655 0.7061 0.9093

- - - -

THREADING

Copper Alloy

20 - 80 RB 80 - 100 RB

0.43 0.72 0.72 0.22 0.16

45/64 29/32

Titanium Alloy Aluminum Alloy Magnesium Alloy

- - -

* Based on nominal tap drill diameter. ** Based on 0.003" probable mean oversize.

To calculate the percent of full thread for a given hole diameter:

Basic Major Diameter of Thread - Drill Hole Size 0.0130

% Thread =

# of Thread per Inch

X

Notes • The above tap drill informaƟon represents probable thread percentages for the standard tap drills stocked at Allied Machine. Special insert diameters may be required in order to meet a user specific percentage of thread requirements. • The 0.003" probable mean oversize hole condiƟon is based on opƟmum cuƫng condiƟons. Probable percent of full thread may vary based on less ideal cuƫng condiƟons. • The table and equaƟons on this page are found in the Machinery’s Handbook . Permission to simplify and print the equaƟons is granted by the editor of the Machinery’s Handbook .

SPECIALS

www.alliedmachine.com | 1.330.343.4283

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