Biomedical Engineering Reference
In-Depth Information
Whole length of bur
lr
lr
Bur
head
Diameter
d
r
d
x
FIGURE 15.2
Dental burs with dimensional parameters showing the bur head
[14]
.
(A)
(B)
Rake angle
Direction of
rotation
Clearance
angle
20 kV
X50 500
ยต
m
FIGURE 15.3
(A) Geometry of a typical tungsten carbide bur. (B) Schematic diagram showing the rake
angle relative to the cutting direction
[15]
.
The high hardness makes WC extremely wear resistant but it is brittle compared to stainless
steel. Therefore, only the blades of a bur should be made of tungsten carbide and the shank can be
made of steel. Sintering is used to join the carbide blades onto the steel shank. Tungsten carbide
is also suitable for burs designated for use at lower speeds, when they are to be used many times.
