Dake Model Cut 250 - Manual (Page 10)

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CUT 250 CUT 250 CUT 250 CUT 250 CUT 250
9.3 - Teeth pitch
As already stated, this depends on the following factors:
- hardness of the material
- dimensions of the section
- thickness of the wall.
Tooth shape
The profile of the toothing depends on the size, shape and
thickness of the section to be cut, either straight or at an angle.
It may also vary according to the pitch, but not so distinctly as
to make this an element for classification.
- Fine toothing is to be chosen for cutting small sections with a
profiled shape and tubular sections with thin walls (2-5 mm
depending on the material).
- Large toothing is suitable for cutting medium and large solid
sections or fairly thick profiled or tubular sections (over 5 mm).
"A" toothing:
normal fine toothing
S (MM) PICTH SHAPE SPEED
up to 2 4 - 6
B
shaped
2
2 ÷ 5 8
C
solid
2
5 ÷ 10 8
C
solid
1
over 10 8
C
solid
1
up to 20 8
C
solid
1
20 ÷ 50 10
C
solid
1
"AW" toothing:
fine toothing with alternate side
rake
Added toothing:
disks made in this way are
used for cutting non-ferrous
metals, such as light alloys,
and plastics, and above all in
wood-working. The teeth are
hard metal (HM) plates brazed
onto the body of the disk; there
are various types and shapes
and, considering the vastness
of the field, the topic is not
developed further here.
The rake varies especially according to the type of material
to be cut.
Tooth cutting angle
Each tooth has two cutting angles:
-
α αα αα
: front rake angle
-
γγγγγ
: rear rake angle
SHARPENING CIRCULAR SAWS
S S
S
α αα αα
γγγγγ
"B" toothing:
normal large toothing with or
without shaving breaking inci-
sion "BW" toothing:
large toothing with alternate
side rake
“C (HZ)” toothing:
large toothing with roughing
tooth with rake on both sides,
alternating with a finishing
tooth without rake. The rou-
ghing tooth is 0.15-0.30 mm
higher
9.7 - Type of disks
The disks differ essentially in their constructive characteristics,
such as:
- Tooth shape
- Tooth cutting angle
9.4 - Cutting and advance speed
The cutting speed (m/min) and the advance speed (cm 2 /min =
area travelled by the disk teeth when removing shavings) are
limited by the development of heat close to the tips of the teeth.
- The cutting speed is subordinate to the resistance of the
material (R = N/mm 2 ), to its hardness (HRC) and to the
dimensions of the widest section.
- Too high an advance speed (= disk descent) tends to cause
the disk to deviate from the ideal cutting path, producing non
rectilinear cuts on both the vertical and the horizontal plane.
9.5 - Running in the disk
When cutting for the first time, it is good practice to run in
the tool making a series of cuts at a low advance speed
(= 30-35 cm
2 /min on material of average dimensions with respect
to the cutting capacity and solid section of normal steel with
R = 410-510 N/mm
2 ), generously spraying the cutting area
with lubricating coolant.
9.6 - Disk structure
The most commonly used disks are made of extra high speed
steel (HHS) of normal quality (HHS/DMo5) or superior quality
(HHS/Mo5 + Co5) with a treated tooth, which differentiates them
from the former on account of the high value of structural
resistance, greater resistance to seizing, absence of stress in
the mass and a better holding of lubricating coolant during work.
T 3 4 5 6 7 8 9 10 12 14 16
p 1,3 1,6 2,1 2,5 2,9 3,4 3,8 4,2 5,1 5,9 7,2
d 1,5 2 2,5 3 3,5 4 4,5 5 6 7 8
h = 0,2 mm h = 0,3 mm