STEEL QUALITIES

DMo5 - DIN 1.3343 - JIS SKH51 - M2  High speed TUNGSTEN MOLYBDENUM STEEL. It is strongly alloyed high speed steel containing wolfram, vanadium and molybdenum. Circular saws have both very good mechanical characteristics and excelent strength for these alloying elements. Fine structure of martensite, its formation is ensured by 5% molybdenum content, makes the blades resistant from disruption and fatigue of material. Wolfram content not only forms extremely hard carbides and improves blade strength, but above all keeps material grain growth off. Moreover increases the resistant to attritions, especially during big cutting temperatures. Analogous to above mentioned elements vanadium takes part in improvement of mechanichal characteristics as well. It makes fine grains, participates in rise of hard carbides and increases the instrument resistant to attritions. For high performance saw blades. Hardened and tempered to 64 +/- 1

EMo5Co5 - DIN 1.3243 - J1S SKH55 - M35 TUNGSTEN MOLYBDENUM COBALT bearing steel. It is strongly alloyed high speed steel with content of wolfram, molybdenum and cobalt. From the HSS/Dmo5 steel mentioned above differs by 5% cobalt content which keeps material grain growth off during high cutting temperatures and improves cutting operation. These characteristics are prerequisite for efficient cutting of hard materials as are stainless steels or steel of big strength. Special high performance saw blades. Hardened and tempered to 65 +/- 1

SURFACE TREATMENT VAPO

VAPO is a controlled oxidation process produces a layer of iron oxide (Fe3O4) on the surface of a saw blade. It is a surface modification by CO2 oxidation when made circular saws are once more let to tempering in overheated steam in cca 550°C. Thus is created extremely fine surface layer with hardness 900 HV. Because of stress release circular saws improved by this modification get a better elasticity which avoid their possible break. Microporosity arised on surface enables better coolant water distribution. This increases its self-lubricating capability and greatly improves its resistance to “pick-up”. Slipslide is a very low cost surface treatment suitable for most general cutting work.  But exception is cutting of alumunium, copper, brass and their alloys. Technical characteristics: Surface Hardness: 900 HV; Coefficient of friction : 0.65;

Physical Vapour Deposition COATINGS  PVD

TiN Titanium Nitride (GOLDSKIN):  Circular saws coated by TiN (titanium-nitride) reach very high surface microhardness which enables their using for separation of material of high mechanical tenacity. It is very suitable for cutting medium-alloyed and hard steel. The coat characteristics enable to heighten circumferential speed and feed rate nearly by 50 % and it very shortens the time of working cycles. This coating with a titanium base 3 microns thick obtained at a process temperature of approximately 490°C. It guarantees a friction coefficient of 0,47 and an oxidation temperature of 640°C. The hardness of the coated layer reaches 2.480 Vickers (HV 0,05). Its low thermal conductivity provides a reliable heat shield for the sublayer. It is a coating suitable for cutting low alloy steel and must always be used with plenty of lubrication. It is not suitable for cutting copper, brass or bronze.

TiCN Titanium Carbo Nitride (SPEEDSKIN): PVD coating with very low coefficient friction on steel. It enables to reach very clear cuts and avoid cool surfacing even in high circumferential cutting speed and shifts in such materials as are very hard steels, copper and brass, its cutting often create cool surfacing. It enables to heighten circumferential speed and feed speed nearly by 100 % in face of parameters for blank circular saws

TiAIN Titanium Aluminium Nitride (BLACKSKIN): This coating is suitable for separation of materials of high strenght in traction, stainless steels and material with resistant to attritions, as are cast iron and brass. Its excellent characteristic is resistance in high work temperatures that is why it is suitable for use in dry cuts or in cuts with insufficient cooling. Moreover, it is very suitable for high circumferential speed. This multilayer coating is 3 microns thick. The plasma is obtained from the fusion of a titanium/aluminium cathode. The addition of an inert gas during the process and the energy with which the molecules are loaded allow the surface to be bombarded, thereby obtaining excellent coating properties that guarantee high thermal resistance to the sublayer; it has an oxidation temperature of 800°C resulting in a surface hardness of 3.400 Vickers (HV 0,05). The friction coefficient is 0,45 and allows circular saws to be used with excellent results even in conditions of limited or minimal lubrication and misting. It is particularly suited to high alloy steels of up to 1100 N/mm2, cutting cast iron, stainless steel and all materials that develop considerable heat.

CRN Chrome Nitride (GRAYSKIN): Very low friction coefficient makes circular saw baldes with GRAYSKIN coating very suitable for cutting materials which have strong tendency for being stuck on tool sides, it means brass, copper and alluminium alloys. The possibility of coating tools in stronger layers from 2,5 microns thick up to the thickness 7µm is its next advantage. It is made by means of a plasma of titanium and carbon that increases the hardness to 3.000 Vickers (HV 0,05). The friction coefficient 0,22 is very low due to the high carbon content. This makes it very suitable for cutting highly abrasive materials such as stainless steel and medium alloyed steels with a hardness of up to 800 N/mm2. The low friction coefficient considerably reduces chipping at the cutting edge and the disc sidewall. This coating has an oxidation temperature of 400°C and should always be used with plenty of lubrication during the cutting process.

Tooth shape A is normally used on fine toothing (< T3) for applications such as brass alloy cutting, jewellery and screw slotting.	Tooth shape B is normally used for thin-walled pipes and the cutting of structural shapes, especially where chip removal is not an issue.	Tooth shape AW, unlike type A, is alternately bevelled, thus optimizing chip shredding. It is particularly suitable for precision cutting.

Tooth shape BW is primarily used for cutting pipes and sections. The tooth is alternately bevelled at 45°, breaks the chip in two and guarantees good chip evacuation.	Tooth shape C is used for solid sections or very thick pipes. The chip is shredded into three parts due to the presence of both a finishing tooth without chamfer and a pre-cutting tooth (longer than 0.25 mm) with two chamfers on each side.	Tooth shape BR has been successfully introduced for cutting pipes. It has double the number of cutting edges and guarantees a higher number of cuts and a better finish to the section. It also improves tool durability by about 20% because it reduces the removed section per each single sharpening.	Tooth shape VP, variable pitch, is used to cut very irregular sections which cause severe vibration and noise. It guarantees softer contact and offers a good compromise between cut duration and reduced vibration.

CUTTING SPEED AND FEED RATE In order to find the correct working parameters for each single application, the user normally has to carry out numerous careful comparative checks. The factors to be considered (material, machine, tool etc) directly determine the result. Our engineers, attentive to our customers’ requirements, have created very sophisticated software which analyzes all this data simultaneously and allows us to considerably reduce the optimization time during the various applications. Our engineers can recommend the best cutting parameters for each single application. The following formula and graphs indicate how to calculate the cutting speed, number of revolutions and feed rate.

V = Cutting speed (mt/1’)
D1 = Saw blade diameter (mm)
Av = Feed rate (mm/1’)
Avz = Feed rate per tooth (mm/Z)
Z = Number of teeth
Rpm = Number of revolutions/minute

Formula:
Rpm V x 1000
-------------------
D1 x 3,14

Av = Avz x Z x rpm

CHOICE OF PITCH AND FEED RATE
Once the material and the section to be cut have been identified, the pitch must be chosen. The correct pitch will prevent dangerous vibration and guarantee correct chip evacuation. The following data are approximate. Our engineers can advise on the most appropriate pitch for each specific application (stationary cut, flying cut, transfer) and the materials to be cut.

d	d	T	s	T
≤ 20 mm	≤ 1,0 mm	3	> 1 mm	4
≤ 30 mm	≤ 1,5 mm	5	> 1,5 mm	5,5
≤ 40 mm	≤ 2,0 mm	6	> 2 mm	7
≤ 50 mm	≤ 4,0 mm	6	> 4 mm	7
≤ 60 mm	≤ 4,0 mm	7	> 4 mm	8
≤ 70 mm	≤ 3,0 mm	7	> 3 mm	8
≤ 80 mm	≤ 4,0 mm	8	> 4 mm	10
≤ 90 mm	≤ 4,0 mm	8	> 4 mm	10
≤ 100 mm	≤ 7,0 mm	10	> 7 mm	12
≤ 120 mm	≤ 5,0 mm	10	> 5 mm	12
≤ 140 mm	≤ 4,0 mm	10	> 4 mm	12

	Avz < 0,08 mm/Z	Avz > 0,08 mm/Z
≤ 20 mm	5,5
≤ 30 mm	7
≤ 40 mm	8
≤ 50 mm	9
≤ 60 mm	10	12
≤ 70 mm	11	12
≤ 80 mm	12	14
≤ 90 mm	12	14
≤ 100 mm	14	16
≤ 120 mm	14	16
≤ 140 mm	16	18

		STEEL ≤ 500 N/mm2 INOX		STEEL ≤ 800 N/mm2 INOX		STEEL ≤ 1200 N/mm2 INOX
D1 350 x 2,5
		v = 75 m/min.	v = 50 m/min.	v = 35 m/min.	v = 25 m/min.	v = 18 m/min.	v = 12 m/min.
		Avz = 0,06 mm/Z		Avz = 0,06 mm/Z		Avz = 0,06 mm/Z
T	Z	Av = mm/min	Av = mm/min	Av = mm/min	Av = mm/min	Av = mm/min	Av = mm/min
3	350	1428	-	670		290	190
4	280	1140	765	535	380	230	150
5	220	600	600	420	300	180	120
6	180	735	490	345	245	147	98
7	160	650	435	305	220	130	87
8	140	570	380	265	190	115	75
9	120	490	330	230	165	100	65
10	110	450	330	210	150	90	60
12	90	365	245	170	120	74	50
14	80	325	220	150	110	66	45
16	70	285	190		95	57	38
18	60	-	165		80	50	33

		BRASS		BRONZE / COOPER		ALUMINIUM
D1 350 x 2,5
		v = 600 m/min.	v = 400 m/min.	v = 400 m/min.	v = 200 m/min.	v = 800 m/min.	v = 500 m/min.
		Avz = 0,06 mm/Z		Avz = 0,06 mm/Z		Avz = 0,06 mm/Z
T	Z	Av = mm/min	Av = mm/min	Av = mm/min	Av = mm/min	Av = mm/min	Av = mm/min
3	350	9100		6000		13300
4	280	7300		4800		10600
5	220	6100	4000	4000	2000	8350	5940
6	180	4800	3200	3200	1600	6840	4860
7	160	4200	2800	2800	1400	6080	4320
8	140	3600	2400	2400	1200	5320	3780
9	120	3300	2200	2200	1100	4560	3240
10	110	3000	2000	2000	1000	4180	2970
12	90	2400	1600	1600	800	3420	2430
14	80	1400		700			2160
16	70	1200		600			1890
18	60	1100		550			1620

The cutting speed (Vt) is expressed in revolutions per minute and represents the speed of the tooth against the piece being cut; cutting speed does not directly influence cutting time.
Cutting speed (rpm) is expressed in revolutions per minute and represents the disc rotating speed around its own axis; it can be determined by a rev counter, or obtained with the following formula.
The feed rate (Av) is expressed in millimetres per minute and represents the feeding speed of the saw while it breaks into the piece being cut. This figure is directly proportional to the cutting time: the higher the feed rate, the lower the contact time.