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Cobalt Drill Bit

Cobalt drill bits, made from heat resistant cobalt steel are heavy duty construction and made to NAS Type J aircraft specifications. Used for drilling holes in hard, tough materials such as stainless steel, titanium high temperature and high strength alloys. High red hardness of cobalt permits speeds 30% greater than HSS drills.

Products
Fractional Sizes
Wire Sizes
Letter Sizes
Drill Feeds & Speeds

Fractional Sizes

Fractional SizesCobalt Drill Bit

Size	Decimal Equivalent	Flute Length	Overall Length
1/16	0.0625	7/8	1 7/8
5/64	0.0781	1	2
3/32	0.0938	1 1/4	2 1/4
7/64	0.1094	1 1/2	2 5/8
1/8	0.1250	1 5/8	2 3/4
9/64	0.1406	1 3/4	2 7/8
5/32	0.1563	2	3 1/8
11/64	0.1719	2 1/8	3 1/4
3/16	0.1875	2 5/16	3 1/2
13/64	0.2031	2 7/16	3 5/8
7/32	0.2188	2 1/2	3 3/4
15/64	0.2344	2 5/8	3 7/8
1/4	0.2500	2 3/4	4
17/64	0.2656	2 7/8	4 1/8
9/32	0.2813	2 15/16	4 1/4
19/64	0.2969	3 1/16	4 3/8
5/16	0.3125	3 3/16	4 1/2
21/64	0.3281	3 5/16	4 5/8
11/32	0.3438	3 7/16	4 3/4
23/64	0.3594	3 1/2	4 7/8
3/8	0.3750	3 5/8	5
25/64	0.3906	3 3/4	5 1/8
13/32	0.4063	3 7/8	5 1/4
27/64	0.4219	3 15/16	5 3/8
7/16	0.4375	4 1/16	5 1/2
29/64	0.4531	4 3/16	5 5/8
15/32	0.4688	4 5/16	5 3/4
31/64	0.4844	4 3/8	5 7/8
1/2	0.5000	4 1/2	6

All dimensions are in inches.

Wire Sizes

Wire SizesCobalt Drill Bit

Size	Decimal Equivalent	Flute Length	Overall Length
1	0.2280	2 5/8	3 7/8
2	0.2210	2 1/2	3 7/8
3	0.2130	2 1/2	3 3/4
4	0.2090	2 1/2	3 3/4
5	0.2055	2 1/2	3 3/4
6	0.2040	2 1/2	3 3/4
7	0.2010	2 7/16	3 5/8
8	0.1990	2 7/16	3 5/8
9	0.1960	2 7/16	3 5/8
10	0.1935	2 7/16	3 5/8
11	0.1910	2 5/16	3 1/2
12	0.1890	2 5/16	3 1/2
13	0.1850	2 5/16	3 1/2
14	0.1820	2 3/16	3 3/8
15	0.1800	2 3/16	3 3/8
16	0.1770	2 3/16	3 3/8
17	0.1730	2 3/16	3 3/8
18	0.1695	2 1/8	3 1/4
19	0.1660	2 1/8	3 1/4
20	0.1610	2 1/8	3 1/4
21	0.1590	2 1/8	3 1/4
22	0.1570	2	3 1/8
23	0.1540	2	3 1/8
24	0.1520	2	3 1/8
25	0.1495	1 7/8	3
26	0.1470	1 7/8	3
27	0.1440	1 7/8	3
28	0.1405	1 3/4	2 7/8
29	0.1360	1 3/4	2 7/8
30	0.1285	1 5/8	2 3/4
31	0.1200	1 5/8	2 3/4
32	0.1160	1 5/8	2 3/4
33	0.1130	1 1/2	2 5/8
34	0.1110	1 1/2	2 5/8
35	0.1100	1 1/2	2 5/8
36	0.1065	1 7/16	2 1/2
37	0.1040	1 7/16	2 1/2
38	0.1015	1 7/16	2 1/2
39	0.0995	1 3/8	2 3/8
40	0.0980	1 3/8	2 3/8
41	0.0960	1 3/8	2 3/8
42	0.0935	1 1/4	2 1/4
43	0.0890	1 1/4	2 1/4
44	0.0860	1 1/8	2 1/8
45	0.0820	1 1/8	2 1/8
46	0.0810	1 1/8	2 1/8
47	0.0785	1	2
48	0.0760	1	2
49	0.0730	1	2
50	0.0700	1	2
51	0.0670	1	2
52	0.0635	7/8	1 7/8
53*	0.0595	7/8	1 7/8
54*	0.0550	7/8	1 7/8
55*	0.0520	7/8	1 7/8
56*	0.0465	3/4	1 3/4
57*	0.0430	3/4	1 3/4
58*	0.0420	11/16	1 5/8
59*	0.0410	11/16	1 5/8
60*	0.0400	11/16	1 5/8

*Not Split Point
All dimensions are in inches.

Letter Sizes

Letter SizesCobalt Drill Bit

Size	Decimal Equivalent	Flute Length	Overall Length
A	0.2340	2 5/8	3 7/8
B	0.2380	2 3/4	4
C	0.2420	2 3/4	4
D	0.2460	2 3/4	4
E	0.2500	2 3/4	4
F	0.2570	2 7/8	4 1/8
G	0.2610	2 7/8	4 1/8
H	0.2660	2 7/8	4 1/8
I	0.2720	2 7/8	4 1/8
J	0.2770	2 7/8	4 1/8
K	0.2810	2 15/16	4 1/4
L	0.2900	2 15/16	4 1/4
M	0.2950	3 1/16	4 3/8
N	0.3020	3 1/16	4 3/8
O	0.3160	3 3/16	4 1/2
P	0.3230	3 5/16	4 5/8
Q	0.3320	3 7/16	4 3/4
R	0.3390	3 7/16	4 3/4
S	0.3480	3 1/2	4 7/8
T	0.3580	3 1/2	4 7/8
U	0.3680	3 5/8	5
V	0.3770	3 5/8	5
W	0.3860	3 3/4	5 1/8
X	0.3970	3 3/4	5 1/8
Y	0.4040	3 7/8	5 1/4
Z	0.4130	3 7/8	5 1/4

All dimensions are in inches.

Drill Feeds & Speeds

Material	Hardness	Drill Type	Point Style	Point Angle	Speed (SFM)	Feed	Coolant
Aluminum / Aluminum Alloys	-	High Helix	Standard	118°	200-300	Medium to Heavy	Water Soluble
Aluminum Bronze	-	High Helix	Standard	118°	50-100	Medium to Heavy	Water Soluble
Brass, Free Machining	-	Low Helix	Standard	118°	100-250	Medium to Heavy	Water Soluble
Bronze, Soft Medium	Below 200	General Purpose	Standard	118°	70-150	Medium to Heavy	Water Soluble
Bronze, High Tensile	-	Low Helix or Half RD	Standard	118°	50-100	Medium to Heavy	Water Soluble
Copper / Copper Alloys	-	General Purpose	Standard	118°	100-200	Medium	Water Soluble
High Temp Alloys, Cobalt Base	180-300	Cobalt	Split Point	135°	5-20	Medium	Activated Oils
High Temp Alloys, Iron Base	180-300	Cobalt	Split Point	135°	5-20	Medium	Activated Oils
High Temp Alloys, Nickel Base	180-300	Nitro® or Cobalt	Split Point	135°	5-15	Medium	Activated Oils
Iron, Soft Case	Up to 150	Heavy Duty or Nitro®	Split Point	135°	75-150	Medium	Dry / Air
Iron, Medium Case	150-250	Heavy Duty or Nitro®	Split Point	135°	50-100	Medium	Dry / Air
Iron, Hard Case	Over 250	Carbide	Standard	118°	40-75	Light to Medium	Dry / Air
Plastic & Related Materials	-	Low Helix	Low Angle	90°	100-200	Medium to Heavy	Dry / Air
Steel, Low Carbon Alloy	125-275	General Purpose	Standard	118°	50-70	Medium	Water Soluble
Steel, Medium Carbon Alloy	275-325	Heavy Duty or Nitro®	Split Point	135°	40-55	Medium	Water Soluble
Steel, High Carbon Alloy	Over 325	Cobalt	Split Point	135°	30-50	Medium	Water Soluble
Steel, Low & Medium Carbon Alloy	Below 175	General Purpose	Standard	118°	45-95	Medium to Heavy	Water Soluble
Steel, High Carbon Alloy	175-225	General Purpose	Standard	118°	45-65	Medium	Water Soluble
Stainless Steel, Austenitic	Below 300	Heavy Duty or Nitro®	Split Point	135°	40-60	Medium to Heavy	Water Soluble
Stainless Steel, Precipitation	Over 300	Cobalt	Split Point	135°	20-40	Medium	Cutting Oil

Feeds – Feed rates for drilling are governed by the drill diameter, machinability of materials and depth of hole.
Speeds – The speed of a drill is determined by the rate which the outer periphery of the tool rotates in relation to material being cut. In general, the SFM at which a drill will operate is within a range based upon the workpiece material, its condition, hardness and depth of hole. It is usually advisable to start the drilling process at a slower SFM and then increase to the maximum.
RPM = (SFM x 3.82) divided by TD = Revolutions Per Minute
SFM = RPM x TD x .262 = Surface Feet Per Minute
TD – Tool diameter in inches

Cobalt Drill Bit

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Size Bit Decimal Overall Length Shank Type Item # Availability Price Quantity UOM

Set 1/16 - 1/2

Set w/ Metal Index

Straight

DRILSETC

In Stock

$192.23199/EA

See Quantity Discounts

29PC COBALT DRILL BIT SET 1/16-1/2 BY 64THS

$192.23199/EA

Qty

In Stock

Product Detail

Quantity	Price
Quantity	Price
20	$186.4541/ EA
30	$170.22026/ EA
60	$144.95705/ EA

Set 1/16 - 1/2

Set w/ Round Index

Straight

DRILSETCR

In Stock

$196.73367/EA

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DRILL SET 29 PC, COBALT, ROUND 1/16-1/2 BY 64THS

$196.73367/EA

Qty

In Stock

Product Detail

Quantity	Price
Quantity	Price
20	$190.82047/ EA
30	$174.20647/ EA
70	$148.35165/ EA

1/16

0.0625

1 7/8

Straight

DRIL1/16C

In Stock

$2.16086/EA

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1/16 COBALT JOBBER DRILL BIT

$2.16086/EA

Qty

In Stock

Product Detail

5/64

0.0781

Straight

DRIL5/64C

In Stock

$2.51425/EA

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5/64 COBALT JOBBER DRILL BIT

$2.51425/EA

Qty

In Stock

Product Detail

3/32

0.0938

2 1/4

Straight

DRIL3/32C

In Stock

$2.24038/EA

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3/32 COBALT JOBBER DRILL BIT

$2.24038/EA

Qty

In Stock

Product Detail

7/64

0.1094

2 5/8

Straight

DRIL7/64C

In Stock

$2.16621/EA

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7/64 COBALT JOBBER DRILL BIT

$2.16621/EA

Qty

In Stock

Product Detail

1/8

0.1250

2 3/4

Straight

DRIL1/8C

In Stock

$3.27792/EA

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1/8 COBALT JOBBER DRILL BIT

$3.27792/EA

Qty

In Stock

Product Detail

9/64

0.1406

2 7/8

Straight

DRIL9/64C

In Stock

$2.81031/EA

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9/64 COBALT JOBBER DRILL BIT

$2.81031/EA

Qty

In Stock

Product Detail

5/32

0.1563

3 1/8

Straight

DRIL5/32C

In Stock

$3.88385/EA

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5/32 COBALT JOBBER DRILL BIT

$3.88385/EA

Qty

In Stock

Product Detail

11/64

0.1719

3 1/4

Straight

DRIL11/64C

In Stock

$3.62305/EA

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11/64 COBALT JOBBER DRILL BIT

$3.62305/EA

Qty

In Stock

Product Detail

3/16

0.1875

3 1/2

Straight

DRIL3/16C

In Stock

$4.99093/EA

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3/16 COBALT JOBBER DRILL BIT

$4.99093/EA

Qty

In Stock

Product Detail

13/64

0.2031

3 5/8

Straight

DRIL13/64C

In Stock

$4.66058/EA

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13/64 COBALT JOBBER DRILL BIT

$4.66058/EA

Qty

In Stock

Product Detail

7/32

0.2188

3 3/4

Straight

DRIL7/32C

In Stock

$5.97286/EA

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7/32 COBALT JOBBER DRILL BIT

$5.97286/EA

Qty

In Stock

Product Detail

15/64

0.2344

3 7/8

Straight

DRIL15/64C

In Stock

$5.18109/EA

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15/64 COBALT JOBBER DRILL BIT

$5.18109/EA

Qty

In Stock

Product Detail

1/4

0.2500

Straight

DRIL1/4C

In Stock

$6.67731/EA

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1/4 COBALT JOBBER DRILL BIT

$6.67731/EA

Qty

In Stock

Product Detail

17/64

0.2656

4 1/8

Straight

DRIL17/64C

In Stock

$8.08745/EA

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17/64 COBALT JOBBER DRILL BIT

$8.08745/EA

Qty

In Stock

Product Detail

9/32

0.2813

4 1/4

Straight

DRIL9/32C

In Stock

$9.33905/EA

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9/32 COBALT JOBBER DRILL BIT

$9.33905/EA

Qty

In Stock

Product Detail

19/64

0.2969

4 3/8

Straight

DRIL19/64C

In Stock

$8.47815/EA

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19/64 COBALT JOBBER DRILL BIT

$8.47815/EA

Qty

In Stock

Product Detail

5/16

0.3125

4 1/2

Straight

DRIL5/16C

In Stock

$12.35484/EA

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5/16 COBALT JOBBER DRILL BIT

$12.35484/EA

Qty

In Stock

Product Detail

21/64

0.3281

4 5/8

Straight

DRIL21/64C

In Stock

$10.54314/EA

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21/64 COBALT JOBBER DRILL BIT

$10.54314/EA

Qty

In Stock

Product Detail

11/32

0.3438

4 3/4

Straight

DRIL11/32C

In Stock

$11.66207/EA

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11/32 COBALT JOBBER DRILL BIT

$11.66207/EA

Qty

In Stock

Product Detail

23/64

0.3594

4 7/8

Straight

DRIL23/64C

In Stock

$13.35693/EA

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23/64 COBALT JOBBER DRILL BIT

$13.35693/EA

Qty

In Stock

Product Detail

3/8

0.3750

Straight

DRIL3/8C

In Stock

$14.59797/EA

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3/8 COBALT JOBBER DRILL BIT

$14.59797/EA

Qty

In Stock

Product Detail

25/64

0.3906

5 1/8

Straight

DRIL25/64C

In Stock

$15.34564/EA

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25/64 COBALT JOBBER DRILL BIT

$15.34564/EA

Qty

In Stock

Product Detail

13/32

0.4063

5 1/4

Straight

DRIL13/32C

In Stock

$20.33263/EA

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13/32 COBALT JOBBER DRILL BIT

$20.33263/EA

Qty

In Stock

Product Detail

27/64

0.4219

5 3/8

Straight

DRIL27/64C

In Stock

$15.92905/EA

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27/64 COBALT JOBBER DRILL BIT

$15.92905/EA

Qty

In Stock

Product Detail

7/16

0.4375

5 1/2

Straight

DRIL7/16C

In Stock

$20.06382/EA

See Quantity Discounts

7/16 COBALT JOBBER DRILL BIT

$20.06382/EA

Qty

In Stock

Product Detail

29/64

0.4531

5 5/8

Straight

DRIL29/64C

In Stock

$19.71123/EA

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29/64 COBALT JOBBER DRILL BIT

$19.71123/EA

Qty

In Stock

Product Detail

15/32

0.4688

5 3/4

Straight

DRIL15/32C

In Stock

$19.58654/EA

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15/32 COBALT JOBBER DRILL BIT

$19.58654/EA

Qty

In Stock

Product Detail

31/64

0.4844

5 7/8

Straight

DRIL31/64C

In Stock

$20.53069/EA

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31/64 COBALT JOBBER DRILL BIT

$20.53069/EA

Qty

In Stock

Product Detail

1/2

0.5000

Straight

DRIL1/2C

In Stock

$25.97745/EA

See Quantity Discounts

1/2 COBALT JOBBER DRILL BIT

$25.97745/EA

Qty

In Stock

Product Detail

0.2280

3 7/8

Straight

DRIL001C

In Stock

$7.50151/EA

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#1 COBALT JOBBER DRILL BIT

$7.50151/EA

Qty

In Stock

Product Detail

0.2010

3 5/8

Straight

DRIL007C

In Stock

$5.62613/EA

See Quantity Discounts

#7 COBALT JOBBER DRILL BIT

$5.62613/EA

Qty

In Stock

Product Detail

#11

0.1910

3 1/2

Straight

DRIL011C

In Stock

$4.56279/EA

See Quantity Discounts

#11 COBALT JOBBER DRILL BIT

$4.56279/EA

Qty

In Stock

Product Detail

#21

0.1590

3 1/4

Straight

DRIL021C

In Stock

$3.97762/EA

See Quantity Discounts

#21 COBALT JOBBER DRILL BIT

$3.97762/EA

Qty

In Stock

Product Detail

#29

0.1360

2 7/8

Straight

DRIL029C

In Stock

$3.62976/EA

See Quantity Discounts

#29 COBALT JOBBER DRILL BIT

$3.62976/EA

Qty

In Stock

Product Detail

#32

0.1160

2 3/4

Straight

DRIL032C

In Stock

$2.7677/EA

See Quantity Discounts

#32 COBALT JOBBER DRILL BIT

$2.7677/EA

Qty

In Stock

Product Detail

#44

0.0860

2 1/8

Straight

DRIL044C

2-4 Working Days

$3.95115/EA

See Quantity Discounts

#44 COBALT JOBBER DRILL BIT

$3.95115/EA

Qty

2-4 Working Days

Product Detail

#55

0.0520

1 7/8

Straight

DRIL055C

In Stock

$2.55596/EA

See Quantity Discounts

#55 COBALT JOBBER DRILL BIT

$2.55596/EA

Qty

In Stock

Product Detail

0.2570

4 1/8

Straight

DRILF-C

2-4 Working Days

$4.79372/EA

See Quantity Discounts

F COBALT JOBBER DRILL BIT

$4.79372/EA

Qty

2-4 Working Days

Product Detail

0.3680

Straight

DRILU-C

In Stock

$16.28378/EA

See Quantity Discounts

U COBALT JOBBER DRILL BIT

$16.28378/EA

Qty

In Stock

Product Detail

Cobalt Drill Bit

Cobalt Drill Bit

Technical Data

Fractional Sizes

Fractional SizesCobalt Drill Bit

Wire Sizes

Wire SizesCobalt Drill Bit

Letter Sizes

Letter SizesCobalt Drill Bit

Drill Feeds & Speeds

Drill Feeds & Speeds

Size

Overall Length

Style

29PC COBALT DRILL BIT SET 1/16-1/2 BY 64THS

DRILL SET 29 PC, COBALT, ROUND 1/16-1/2 BY 64THS

1/16 COBALT JOBBER DRILL BIT

5/64 COBALT JOBBER DRILL BIT

3/32 COBALT JOBBER DRILL BIT

7/64 COBALT JOBBER DRILL BIT

1/8 COBALT JOBBER DRILL BIT

9/64 COBALT JOBBER DRILL BIT

5/32 COBALT JOBBER DRILL BIT

11/64 COBALT JOBBER DRILL BIT

3/16 COBALT JOBBER DRILL BIT

13/64 COBALT JOBBER DRILL BIT

7/32 COBALT JOBBER DRILL BIT

15/64 COBALT JOBBER DRILL BIT

1/4 COBALT JOBBER DRILL BIT

17/64 COBALT JOBBER DRILL BIT

9/32 COBALT JOBBER DRILL BIT

19/64 COBALT JOBBER DRILL BIT

5/16 COBALT JOBBER DRILL BIT

21/64 COBALT JOBBER DRILL BIT

11/32 COBALT JOBBER DRILL BIT

23/64 COBALT JOBBER DRILL BIT

3/8 COBALT JOBBER DRILL BIT

25/64 COBALT JOBBER DRILL BIT

13/32 COBALT JOBBER DRILL BIT

27/64 COBALT JOBBER DRILL BIT

7/16 COBALT JOBBER DRILL BIT

29/64 COBALT JOBBER DRILL BIT

15/32 COBALT JOBBER DRILL BIT

31/64 COBALT JOBBER DRILL BIT

1/2 COBALT JOBBER DRILL BIT

#1 COBALT JOBBER DRILL BIT

#7 COBALT JOBBER DRILL BIT

#11 COBALT JOBBER DRILL BIT

#21 COBALT JOBBER DRILL BIT

#29 COBALT JOBBER DRILL BIT

#32 COBALT JOBBER DRILL BIT

#44 COBALT JOBBER DRILL BIT

#55 COBALT JOBBER DRILL BIT

F COBALT JOBBER DRILL BIT

U COBALT JOBBER DRILL BIT