The document discusses various point geometry defects in drill bits and their functional impact. It provides maximum allowable measurements for defects like layback, hook, offcenter, and overlap across different drill bit diameter ranges. Less impactful defects with wider tolerances like gap and negative angle are also outlined. The tables seek to define optimum point geometry and tolerances for drill bit cutting effectiveness.

1. TYC O M INTERNATIONAL
Point Geometry
Basics

2. Chips TYC O M INTERNATIONAL
Functional Defect
Prevents the drill from
cutting cleanly and efficiently
Diameter Magnification
0.0020"-0.0130" 50X
0.0131"-0.0260" 40X
0.0261"-0.0465" 30X
0.0466"-0.1250" 20X
0.1251"-0.1800" 15X
0.1801"-0.2639" 10X

3. Layback TYC O M INTERNATIONAL
Functional Defect
Results in the Center of the
Primary Face Being the Leading
Cutting Edge (Negative Rake).
Diameter Maximum
0.0020"-0.0130" 0.0001"
0.0131"-0.0260" 0.0001"
0.0261"-0.0465" 0.0002"
0.0466"-0.1250" 0.0002"
0.1251"-0.1800" 0.0003"
0.1801"-0.2639" 0.0004"

4. Hook TYC O M INTERNATIONAL
Minor Functional Defect
Extreme Hook Can
Result in Premature Wear
Diameter Maximum
0.0020"-0.0130" 0.0002"
0.0131"-0.0260" 0.0003"
0.0261"-0.0465" 0.0004"
0.0466"-0.1250" 0.0005"
0.1251"-0.1800" 0.0008"
0.1801"-0.2639" 0.0012"

5. Offcenter TYC O M INTERNATIONAL
a
Functional Defect
Can Result in
Non-Concentric Drilling.
Diameter Maximum
0.0020"-0.0130" 0.0002"
b 0.0131"-0.0260" 0.0003"
0.0261"-0.0465" 0.0004"
0.0466"-0.1250" 0.0005"
0.1251"-0.1800" 0.0008"
0.1801"-0.2639" 0.0012"
(a-b)
Offcenter =
2

6. Offset TYC O M INTERNATIONAL
a
Functional Defect
Can Result in
Non-Concentric Drilling.
Diameter Maximum
0.0020"-0.0130" 0.0002"
0.0131"-0.0260" 0.0003"
b 0.0261"-0.0465" 0.0004"
0.0466"-0.1250" 0.0005"
0.1251"-0.1800" 0.0008"
0.1801"-0.2639" 0.0012"
(a-b)
Offset =
2

7. Overlap TYC O M INTERNATIONAL
Moderately Functional Defect
Can Impede the Drill
from Centering Properly
Diameter Maximum
0.0020"-0.0130" 0.0002"
0.0131"-0.0260" 0.0003"
0.0261"-0.0465" 0.0004"
0.0466"-0.1250" 0.0005"
0.1251"-0.1800" 0.0008"
0.1801"-0.2639" 0.0012"

8. Gap TYC O M INTERNATIONAL
Non-Functional Condition
Diameter Maximum
0.0020"-0.0130" 0.0002"
0.0131"-0.0260" 0.0003"
0.0261"-0.0465" 0.0004"
0.0466"-0.1250" 0.0005"
0.1251"-0.1800" 0.0008"
0.1801"-0.2639" 0.0012"

9. Negative TYC O M INTERNATIONAL
Non-Functional Condition
Diameter Maximum
0.0020"-0.0130" 1deg
0.0131"-0.0260" 1deg
0.0261"-0.0465" 1deg
0.0466"-0.1250" 2deg
0.1251"-0.1800" 2deg
0.1801"-0.2639" 2deg

10. Flare TYC O M INTERNATIONAL
Non-Functional Condition
Diameter Maximum
0.0020"-0.0130" 2deg
0.0131"-0.0260" 3deg
0.0261"-0.0465" 4deg
0.0466"-0.1250" 4deg
0.1251"-0.1800" 5deg
0.1801"-0.2639" 6deg

11. TYC O M INTERNATIONAL
Optimum
Point
Geometry