API Standards for Manufacturing and API Casing Chart
API Standards For Rock Bits And PDC Bits
While in-house engineers decide the various individual differences of pdc bits and tricones, API standards enable drilling professionals the world over to communicate clearly. All major drill bit manufacturers operate within strict plus and minus tolerances as set forth by the American Petroleum Institute. API certified casing will be within the drift on the below API Casing Chart.
These standards, known as API Standards, are part of the backbone of the drilling industry. All reputable PDC and tricone manufacturers follow these guidelines.
The American Petroleum Institute maintains more than 500 standards and recommended practices. It also represents the oil and gas industry to the public, Congress, state governments, and media.
American Petroleum Institute Standards for PDC and Rock Bit Tolerances
Bit Size (In.) | O.D. Tolerance (In.) | |
---|---|---|
6 3/4" and smaller | -0.015 to +0.00 PDC | -0.0 to +1/32 Rock Bit |
6 25/32" to 9" | -0.020 to +0.00 PDC | -0.0 to +1/32 Rock Bit |
9 1/32" to 13 3/4" | -0.030 to +0.00 PDC | -0.0 to +1/32 Rock Bit |
13 25/32" to 17 1/2" | -0.045 to +0.00 PDC | -0.0 to +1/16 Rock Bit |
17 17/32" and larger | -0.063 to +0.00 PDC | -0.0 to +3/32 Rock Bit |
Use either a “go” gauge or a “no go” gauge to gauge PDC bits.
Use a “no go”gauge to ensure a bit is not smaller than allowed. As its name implies, it should not go or slip down the entire length of the bit. A “go gauge ensures a bit is not larger than allowed and should slip down the entire bit.
3 1/2" to 4 1/2" drill bits | 5 5/8" to 7 3/8" drill bits |
4 5/8" to 5 1/2" drill bits | 2 3/8" API Reg. pin |
5 5/8" to 7 3/8" drill bits | 2 7/8" API Reg. pin |
Number of Nozzles | ||||||||
Nozzle Size | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
7 | 0.0376 | 0.0752 | 0.1127 | 0.1503 | 0.1877 | 0.2255 | 0.2631 | 0.3007 |
8 | 0.0491 | 0.0982 | 0.1473 | 0.1963 | 0.2454 | 0.2945 | 0.3435 | 0.3927 |
9 | 0.0621 | 0.1242 | 0.1864 | 0.2485 | 0.3106 | 0.3728 | 0.4249 | 0.497 |
10 | 0.0767 | 0.1534 | 0.2301 | 0.306 | 0.3835 | 0.4602 | 0.5369 | 0.6136 |
11 | 0.0928 | 0.1856 | 0.2784 | 0.3712 | 0.464 | 0.5568 | 0.6496 | 0.7424 |
12 | 0.1104 | 0.2209 | 0.3313 | 0.4418 | 0.5522 | 0.6627 | 0.7731 | 0.8836 |
13 | 0.1296 | 0.2592 | 0.3889 | 0.5185 | 0.6481 | 0.7777 | 0.9073 | 1.037 |
14 | 0.1503 | 0.3007 | 0.451 | 0.6013 | 0.7517 | 0.902 | 1.0523 | 1.2026 |
15 | 0.1726 | 0.3451 | 0.5177 | 0.6903 | 0.8629 | 1.0354 | 1.208 | 1.3806 |
16 | 0.1963 | 0.3927 | 0.589 | 0.7854 | 0.9817 | 1.1781 | 1.3744 | 1.5708 |
18 | 0.2485 | 0.497 | 0.7455 | 0.994 | 1.2425 | 1.491 | 1.7395 | 1.988 |
20 | 0.3068 | 0.6136 | 0.9204 | 1.2272 | 1.534 | 1.8408 | 2.1476 | 2.4544 |
22 | 0.3712 | 0.7424 | 1.1137 | 1.4849 | 1.8561 | 2.2273 | 2.5986 | 2.9698 |
The API Casing Chart below helps determine the drill bit size you need.
API Casing Chart
Number of nozzles | ||||||||
Casing Size OD | Casing Coupling OD | Nominal Weight | Inside Diameter ID | API Drift ID | Roller Cone Bit Size OD | Fixed Cutter Bit Size OD |
||
Inches | Inches | Lbs/ft | Inches | Inches | Inches | Decimal | Inches | Decimal |
4 1/2 | 5 | 9.5 | 4.09 | 3.965 | 3 7/8 | 3.875 | 3 7/8 | 3.875 |
4.5 | 5 | 10.5 | 4.052 | 3.927 | 3 7/8 | 3.875 | 3 7/8 | 3.875 |
5 | 11.6 | 4 | 3.875 | 3 7/8 | 3.875 | 3 7/8 | 3.875 | |
5 | 13.5 | 3.92 | 3.795 | 3 3/4 | 3.75 | 3 3/4 | 3.75 | |
5 | 5.563 | 11.5 | 4.56 | 4.435 | 4 3/8 | 4.375 | 4 3/4 | 4.375 |
5 | 5.563 | 13 | 4.494 | 4.369 | 4 1/4 | 4.25 | 4 1/4 | 4.25 |
5.563 | 15 | 4.408 | 4.283 | 4 1/4 | 4.25 | 4 1/4 | 4.375 | |
5.563 | 18 | 4.276 | 4.151 | 4 1/8 | 4.125 | 4 1/8 | 4.375 | |
5 1/2 | 6.05 | 14 | 5.012 | 4.887 | 4 5/8 | 4.75 | 4 5/8 | 4.75 |
5.5 | 6.05 | 15.5 | 4.95 | 4.825 | 4 5/8 | 4.75 | 4 5/8 | 4.75 |
6.05 | 17 | 4.892 | 4.767 | 4 5/8 | 4.75 | 4 5/8 | 4.75 | |
6.05 | 20 | 4.778 | 4.653 | 4 1/2 | 4.5 | 4 1/2 | 4.5 | |
6.05 | 23 | 4.67 | 4.545 | 4 1/2 | 4.5 | 4 1/2 | 4.5 | |
6 5/8 | 7.39 | 20 | 6.049 | 5.924 | 5 7/8 | 5.875 | 5 7/8 | 5.875 |
6.625 | 7.39 | 24 | 5.921 | 5.796 | 4 3/4 | 4.75 | 4 3/4 | 4.75 |
7.39 | 28 | 5.791 | 5.666 | 4 3/4 | 4.75 | 4 3/4 | 4.75 | |
7.39 | 32 | 5.675 | 5.55 | 4 3/4 | 4.75 | 4 3/4 | 4.75 | |
7 | 7.656 | 17 | 6.538 | 6.413 | 6 1/4 | 6.25 | 6 1/4 | 6.25 |
7 | 7.656 | 20 | 6.456 | 6.331 | 6 1/4 | 6.25 | 6 1/4 | 6.25 |
7.656 | 23 | 6.366 | 6.241 | 6 1/8 | 6.125 | 6 1/8 | 6.125 | |
7.656 | 26 | 6.276 | 6.151 | 6 1/8 | 6.125 | 6 1/8 | 6.125 | |
7.656 | 29 | 6.184 | 6.059 | 6 | 6 | 6 | 6 | |
7.656 | 32 | 6.094 | 5.969 | 5 7/8 | 5.875 | 5 7/8 | 5.875 | |
7.656 | 35 | 6.004 | 5.879 | 5 7/8 | 5.875 | 5 7/8 | 5.875 | |
7.656 | 38 | 5.92 | 5.795 | 4 3/4 | 4.75 | 4 3/4 | 4.75 | |
7 5/8 | 8.5 | 20 | 7.125 | 7 | 6 3/4 | 6.75 | 6 3/4 | 6.75 |
7.625 | 8.5 | 24 | 7.025 | 6.9 | 6 3/4 | 6.75 | 6 3/4 | 6.75 |
8.5 | 26.4 | 6.969 | 6.844 | 6 3/4 | 6.75 | 6 3/4 | 6.75 | |
8.5 | 29.7 | 6.875 | 6.75 | 6 3/4 | 6.75 | 6 3/4 | 6.75 | |
8.5 | 33.7 | 6.765 | 6.64 | 6 1/2 | 6.5 | 6 1/2 | 6.5 | |
8.5 | 39 | 6.625 | 6.5 | 6 1/2 | 6.5 | 6 1/2 | 6.5 | |
8 5/8 | 9.625 | 24 | 8.097 | 7.972 | 7 7/8 | 7.875 | 7 7/8 | 7.875 |
8.625 | 9.625 | 28 | 8.017 | 7.892 | 7 7/8 | 7.875 | 7 7/8 | 7.875 |
9.625 | 32 | 7.921 | 7.796 | 6 3/4 | 6.75 | 6 3/4 | 6.75 | |
9.625 | 36 | 7.825 | 7.7 | 6 3/4 | 6.75 | 6 3/4 | 6.75 | |
9.625 | 40 | 7.725 | 7.6 | 6 3/4 | 6.75 | 6 3/4 | 6.75 | |
9.625 | 44 | 7.625 | 7.5 | 6 3/4 | 6.75 | 6 3/4 | 6.75 | |
9.625 | 49 | 7.511 | 7.386 | 6 3/4 | 6.75 | 6 3/4 | 6.75 | |
9 5/8 | 10.625 | 29.3 | 9.063 | 8.907 | 8 3/4 | 8.75 | 8 3/4 | 8.75 |
9.625 | 10.625 | 32.3 | 9.001 | 8.845 | 8 3/4 | 8.75 | 8 3/4 | 8.75 |
10.625 | 36 | 8.921 | 8.765 | 8 3/4 | 8.75 | 8 3/4 | 8.75 | |
10.625 | 40 | 8.835 | 8.679 | 8 1/2 | 8.5 | 8 1/2 | 8.5 | |
10.625 | 43.5 | 8.755 | 8.599 | 8 1/2 | 8.5 | 8 1/2 | 8.5 | |
10.625 | 47 | 8.681 | 8.525 | 8 1/2 | 8.5 | 8 1/2 | 8.5 | |
10.625 | 53.5 | 8.535 | 8.379 | 8 3/8 | 8.375 | 8 3/8 | 8.375 | |
10 3/4 | 11.75 | 32.75 | 10.192 | 10.036 | 9 7/8 | 9.875 | 9 7/8 | 9.875 |
10.75 | 11.75 | 40.5 | 10.05 | 9.984 | 9 7/8 | 9.875 | 9 7/8 | 9.875 |
11.75 | 45.5 | 9.95 | 9.794 | 9 1/2 | 9.5 | 9 1/2 | 9.5 | |
11.75 | 51 | 9.85 | 9.694 | 9 1/2 | 9.5 | 9 1/2 | 9.5 | |
11.75 | 55.5 | 9.76 | 9.604 | 9 1/2 | 9.5 | 9 1/2 | 9.5 | |
11.75 | 60.7 | 9.66 | 9.504 | 9 1/2 | 9.5 | 9 1/2 | 9.5 | |
11.75 | 65.7 | 9.56 | 9.404 | 8 3/4 | 8.75 | 8 3/4 | 8.75 | |
11 3/4 | 12.75 | 42 | 11.084 | 10.928 | 10 5/8 | 10.625 | 10 5/8 | 10.625 |
11.75 | 12.75 | 47 | 11 | 10.844 | 10 5/8 | 10.625 | 10 5/8 | 10.625 |
12.75 | 54 | 10.88 | 10.724 | 10 5/8 | 10.625 | 10 5/8 | 10.625 | |
12.75 | 60 | 10.772 | 10.616 | 9 7/8 | 9.875 | 9 7/8 | 9.875 | |
13 3/8 | 14.375 | 48 | 12.715 | 12.559 | 12 1/4 | 12.25 | 12 1/4 | 12.25 |
13.375 | 14.375 | 54.5 | 12.615 | 12.459 | 12 1/4 | 12.25 | 12 1/4 | 12.25 |
14.375 | 61 | 12.515 | 12.359 | 12 1/4 | 12.25 | 12 1/4 | 12.25 | |
14.375 | 68 | 12.415 | 12.259 | 12 1/4 | 12.25 | 12 1/4 | 12.25 | |
14.375 | 72 | 12.347 | 12.191 | 11 | 11 | 10 5/8 | 10.625 | |
16 | 17 | 65 | 15.25 | 15.062 | 14 3/4 | 14.75 | 14 3/4 | 14.75 |
16 | 17 | 75 | 15.124 | 14.936 | 14 3/4 | 14.75 | 14 3/4 | 14.75 |
17 | 84 | 15.01 | 14.822 | 14 3/4 | 14.75 | 14 3/4 | 14.75 | |
18 5/8 | 20 | 87.5 | 17.755 | 17.567 | 17 1/2 | 17.5 | 17 1/2 | 17.5 |
18.625 | - | - | - | - | - | - | - | - |
20 | 21 | 94 | 19.124 | 18.936 | 17 1/2 | 17.5 | 17 1/2 | 17.5 |
20 | 21 | 106.5 | 19 | 18.812 | 17 1/2 | 17.5 | 17 1/2 | 17.5 |
21 | 133 | 18.73 | 18.542 | 17 1/2 | 17.5 | 17 1/2 | 17.5 | |
21 | 169 | 18.376 | 18.188 | 17 1/2 | 17.5 | 17 1/2 | 17.5 |