API Standards For Rock Bits And PDC Bits

API standards, as established by the American Petroleum Institute, enable drilling professionals the world over to communicate clearly.

The American Petroleum Institute:

*maintains more than 500 standards and recommended practices

*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

PDC bits are gauged by either a "go" gauge or a "no go" gauge. 

A "no go"gauge is used to ensure a bit is not smaller than allowed and, as the 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. 

Rock Bit Size and API Standard Connection

3 1/2" to 4 1/2" drill bits - 2 3/8" API Reg. pin
4 5/8" to 5 1/2" drill bits - 2 7/8" API Reg. pin
5 5/8" to 7 3/8" drill bits - 3 1/2" API Reg. pin
Number of Nozzles
Nozzle
Size		 1 2 3 4 5 6 7 8
7 .0376 .0752 .1127 .1503 .1877 .2255 .2631 .3007
8 .0491 .0982 .1473 .1963 .2454 .2945 .3435 .3927
9 .0621 .1242 .1864 .2485 .3106 .3728 .4249 .4970
10 .0767 .1534 .2301 .3060 .3835 .4602 .5369 .6136
11 .0928 .1856 .2784 .3712 .4640 .5568 .6496 .7424
12 .1104 .2209 .3313 .4418 .5522 .6627 .7731 .8836
13 .1296 .2592 .3889 .5185 .6481 .7777 .9073 1.0370
14 .1503 .3007 .4510 .6013 .7517 .9020 1.0523 1.2026
15 .1726 .3451 .5177 .6903 .8629 1.0354 1.2080 1.3806
16 .1963 .3927 .5890 .7854 .9817 1.1781 1.3744 1.5708
18 .2485 .4970 .7455 .9940 1.2425 1.4910 1.7395 1.9880
20 .3068 .6136 .9204 1.2272 1.5340 1.8408 2.1476 2.4544
22 .3712 .7424 1.1137 1.4849 1.8561 2.2273 2.5986 2.9698

To download the Halliburton Energy Services Hydraulics Manual, click here.

Related Pages:

API Standards:  API standards, including pin sizes for drill bits and acceptable tolerances for rock bits and pdc bits.  

Atlas Copco:  Atlas Copco bit selection guide, examples of shirttail protection, and TCI and steel tooth cutting structure. 

Button Bits:  Button bits offer several advantages over PDC drill bits: they are less expensive and can withstand higher impact.

Drag Bits:  Drag Bits manufactured as one solid piece of alloy steel offer greater durability and reliability.  Available in step and chevron styles for hard rock drilling.

Dull Grading:  Dull grading drill bits is important but often overlooked.  This process provides valuable information for proper bit selection.

IADC:  The IADC classification system for tooth and button bits explained as well as dull grading codes and what they mean.

IADC Classification:  The IADC classification system for PDC bits:  pictures and explanation of what it means and how to use it.

PDC Cutters:  Because of PDC cutters, PDC bits drill sixty-five percent of total footage.  Their shearing action is more efficient than the crushing action of tricones.

PDC Drill Bits:  Available in either matrix or steel bodies, PDC drill bits  offer higher rate of penetration than tricones in many different formations.

Tricones:  With the exception of cutting structure, tricone bits are designed in the same manner regardless of manufacturer. 

Well Completion Bits:  Well completion drill bits from Atlas Copco in both tooth and button bits.  Bear Claw, Hurricane, Aardvark, and PDC diamond mill bits from KC Bit & Supply.



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