350 super technics – Dake Model Super Technics 350CE User Manual

Page 10

350 SUPER TECHNICS

9.7 - Type of disks

The disks differ essentially in their constructive characteristics,
such as:
- Tooth shape
- Tooth cutting angle

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

The rake varies especially according to the type of material
to be cut.

1,3

1,6

2,1

2,5

2,9

3,4

3,8

4,2

5,1

5,9

7,2

1,5

2,5

3,5

4,5

h = 0,2 mm

h = 0,3 mm

αα

γγγγγ

Tooth cutting angle
Each tooth has two cutting angles:
-

αα

: front rake angle

γγγγγ

: rear rake angle

SHARPENING CIRCULAR SAWS

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.

“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

"B" toothing:
normal large toothing with or
without shaving breaking inci-
sion

"BW" toothing:
large toothing with alternate
side rake

"AW" toothing:
fine toothing with alternate
side rake

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.

9.4 - Cutting and advance speed

The cutting speed (m/min) and the advance speed (cm

/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

), 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.

S (MM)

PICTH

SHAPE

SPEED

up to 2

4 - 6

shaped

2 ÷ 5

solid

3 - 2

5 ÷ 10

solid

over 10

solid

up to 20

solid

20 ÷ 50

solid

50 ч 65

13 ч

solid

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

/min on material of average dimensions with respect

to the cutting capacity and solid section of normal steel with
R = 410-510 N/mm

), generously spraying the cutting area

with lubricating coolant.

9.2 - Choosing the disk

First of all the pitch of the teeth must be chosen, suitable for
thematerial to be cut, according to these criteria:
- parts with a thin and/or variable section such as profiles, pipes

and plate, need close toothing, so that the number of teeth
used simultaneously in cutting is from 3 to 6;

- parts with large transverse sections and solid sections need

widely spaced toothing to allow for the greater volume of the
shavings and better tooth penetration;

- parts made of soft material or plastic (light alloys, mild bronze,

teflon, wood, etc.) also require widely spaced toothing.

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.