Bit contours above illustrate only a partial listing of the bit styles available from the Acker Drill Company

Note: Kerf width is defined as the difference between 0.D. and I.D. set dimensions divided by two. The step-type design, quite popular in recent years, is also available on request.

Silhouette: Showing DCDMA Standards.

Standard Tools are Satisfactory for Most Conditions
Conditions encountered vary so widely, and present so many different problems, that it is impossible to design a single type of bit for all-around operations. By a careful grouping of the elements essential to making a bit, it is possible to make a standard bit which will perform well under general drilling conditions.

Diamond Setting
All diamonds used in Acker bits are carefully selected and a high level of quality maintained at all times. The diamonds are hand-set in an oriented manner, setting the hardest vector of the diamond toward the work. Continuous inspection is carried on to insure that high standards of workmanship are maintained.

Diamond Size
The diamond size is generally dictated by the formation being drilled.

In softer formations, large diamonds will prevent the bit from blocking up. These large diamonds offer more resistance to shock when drilling fractured rock.

In hard fine-grained rock the hardness increases so it becomes necessary to use more and smaller diamonds. Additional stones provide more cutting "edge' and also distribute the added pressure more evenly over the face of the bit.

On the following pages you will note that several sizes of diamonds with their approximate carat weights are shown for each bit. Larger or smatter diamonds are available for special applications.

Matrix
The matrix has three functions to perform: It must securely hold the diamonds in their present pattern, Resist shock, and Dissipate heat away from the diamonds. While tests have shown that the Rockwell hardness scale is not always a true guide to abrasion resistance, it is the most commonly used. The Acker Drill Company has developed three matrices which have a greater resistance to abrasion without appreciably increasing the hardness scale readings.

The patent pending matrices used are:

B.M. A blended soft matrix
A matrix for nonabrasive formations. (20-30RC)
A.R. Abrasion Resistant
A special blended matrix used when drilling fractured or very abrasive formations. (30-40RC)
H.M. A hard matrix
Used in fairly abrasive formations. (40-50RC)

When drilling in shales or other soft formations, it is often desirable to use a multi-waterway bit. This design permits quick removal of the cuttings, and helps prevent blocking.

In harder rock, the finer size cuttings require less waterways, while the need for greater diamond concentration increases. It is common here to use only two (2) waterways. In free cutting rock, when maximum diamond concentration is desired, no waterways are used.

As a general rule, the following combination of stone size and waterways are used:

10, 15, and 26 SPC - 4 Waterways

44, 62, and more - 2 Waterways

Reinforced Waterways
Tungsten carbide inserts set at the waterways are recommended for extremely abrasive or broken formations.

Grit Facing
Tungsten carbide grit facing is recommended for extremely abrasive formations for the 'M' and 'L' design bits, to prevent the bit body from prematurely wearing thin.

Face Contours
There are many types of face contours currently used in bit design. The four most commonly used are defined by DCOMA as: futt-round, semi-round, flat and semi-ftat crowns.

* Unless otherwise specified, the semi-round contour will be furnished.

DCDMA Standards
The above abbreviation stands for the Diamond Core Drill Manufacturers Association of which Acker Drill Co. is a charter member. This organization has standardized several sizes of diamond core bits throughout this reference. Otherwise all bits conform to the standards and tolerance as established by the Association.

Metric Diamond Core Bits
Acker manufactures a full line of metric size diamond core bits and reamers. Metric bits and reamers feature the same high quality of diamonds and manufacture as employed in DCDMA standards. Ask us to bid on your requirements and prove to your satisfaction that we can reduce cost per foot.