What is HSS steel? Types and analogues of HSS. HSS drills

HSS (High Speed ​​Steel) - denotes a group of high-speed steels, translated as steel for work at high speeds. HSS steel is used to manufacture a wide range of different metal cutting tools. This includes twist drills, core drills, step drills, cutters, countersinks, taps, dies, knives and saw blades.

High-speed steel is produced in the classical way - by pouring steel into ingots, then rolling and forging, as well as by powder metallurgy - here a jet of liquid steel is sprayed with nitrogen. HSS steels are considered to be high carbon, typically HSS steel tools have a hardness of 62-64 HRC. The main advantage in comparison with carbide tools is strength and more low price tools. HSS steels perform well in interrupted cuts; a limitation of the use of HSS may be low cutting speeds compared to carbides.

Characteristics of HSS steels

HSS steels are classified into three main groups:

• Tungsten (T);
• Molybdenum (M);
• High-alloy high-speed steels.

Tungsten steels are now practically not used due to the high price of tungsten and its shortage. The most used are steels general purpose T1 and steel with vanadium and cobalt T15. T15 is used for tools used in high temperatures and increased wear.

In molybdenum steels, molybdenum is the main alloying element, but some may contain equal or even more tungsten and cobalt. Steels with a high vanadium and carbon content are very resistant to abrasion. The type of steel from M41 is distinguished by high hardness when working at high temperatures, or such a term is used - red resistance. Molybdenum steels are also used in the manufacture of tools used in "cold" conditions - rolling dies, cut dies. In such cases, HSS steels are hardened to lower temperatures to increase toughness.

Table of common chemical compositions of HSS steels. Russian counterparts.

A type	Russian analog	Chemical composition, %
		C	Mn	Si	Cr	V	W	Mo	Co	Ni
Tungsten HSS steels
T1	P18	0,75	-	-	4,00	1,00	18,00	-	-	-
T2	R18F2	0,80	-	-	4,00	2,00		-	-	-
T4	R18K5F2	0,75	-	-	4,00	1,00	18,00	-	5,00	-
T5		0,80	-	-	4,00	2,00	18,00	-	8,00	-
T6		0,80	-	-	4,50	1,50	20,00	-	12,00	-
T8		0,75	-	-	4,00	2,00	14,00	-	5,00	-
T15	R12F5K5	1,50	-	-	4,00	5,00	12,00	-	5,00	-
Molybdenum HSS steels
M1		0,80	-	-	4,00	1,00	1,50	8,00	-	-
M2	R6M5	0,85	-	-	4,00	2,00	6,00	5,00	-	-
M3	R6M5F3	1,20	-	-	4,00	3,00	6,00	5,00	-	-
M4		1,30	-	-	4,00	4,00	5,50	4,50	-	-
M6		0,80	-	-	4,00	2,00	4,00	5,00	-	-
M7		1,00	-	-	4,00	2,00	1,75	8,75	-	-
M10		0,85-1,00	-	-	4,00	2,00	-	8,00	-	-
M30		0,80	-	-	4,00	1,25	2,00	8,00	-	-
M33		0,90	-	-	4,00	1,15	1,50	9,50	-	-
M34		0,90	-	-	4,00	2,00	2,00	8,00	-	-
M35	R6M5K5	0,82-0,88	0,15-0,40	0,20-0,45	3,75-4,50	1,75-2,20	5,5-6,75	5,00	4,5-5,5	up to 0.30
M36		0,80	-	-	4,00	2,00	6,00	5,00	-	-
High alloyed HSS steels
M41	R6M3K5F2	1,10	-	-	4,25	2,00	6,75	3,75	5,00	-
M42		1,10	-	-	3,75	1,15	1,50	9,50	8,00	-
M43		1,20	-	-	3,75	1,60	2,75	8,00	8,25	-
M44		1,15	-	-	4,25	2,00	5,25	6,25	12,00	-
M46		1,25	-	-	4,00	3,20	2,00	8,25	8,25	-
M47	P2AM9K5	1,10	-	-	3,75	1,25	1,50	9,5	5,00	-
M48		1,42-1,52	0,15-0,40	0,15-0,40	3,50-4,00	2,75-3,25	9,50-10,5	0,15-0,40	8,00-10,0	up to 0.30
M50		0,78-0,88	0,15-0,45	0,20-0,60	3,75-4,50	0,80-1,25	up to 0.10	3,90-4,75	-	up to 0.30
M52		0,85-0,95	0,15-0,45	0,20-0,60	3,50-4,30	1,65-2,25	0,75-1,50	4,00-4,90	-	up to 0.30
M62		1,25-1,35	0,15-0,40	0,15-0,40	3,50-4,00	1,80-2,00	5,75-6,50	10,0-11,0	-	up to 0.30

A tool with a tungsten (W) content will have very useful cutting properties and qualities such as redness. This allows the tools to maintain sharp hardness and sharp cutting edges at red-hot temperatures (up to 530 ° C). Increases redness and wear resistance even more - Cobalt (K).

M1. It is used for the production of drills for various applications. Steel M1 has a lower resistance to redness than steel M2, but the least susceptible to impacts, is more flexible.

M2. The most common material for making tools from HSS steels. M2 retains its cutting edge for a long time and has good redness resistance, in contrast to other HSS steels with a lower tungsten content. It is usually used for the manufacture of tools for high-performance machine work, for example, in drilling machines.

M7. Used for drills of heavy construction when drilling hard sheet metal. This HSS steel is used where flexibility and extended service life are required.

M50. Used for the manufacture of drills, which are used when drilling on portable equipment. Does not have the same redness resistance as other HSS steels with tungsten content

M35. Steel M35 has a higher resistance to red in relation to M2. At the same time, cobalt somewhat reduces the shock resistance.

M42. Steel M42 "Super Cobalt" has excellent abrasion resistance and high redness. It is used when working on viscous and complex materials.

Symbols

The designation of foreign manufacturers does not fully disclose chemical composition HSS steel from which the products are made. This or that tool is assigned a specific task, which is described in the catalog. Other details can be found out by determining the chemical composition, this can be done using a portable metal analyzer, or you can test products empirically. Such marking, of course, can be convenient for an unscrupulous manufacturer, who may indicate, but it will not answer necessary requirements... Below are the main markings that characterize the material from which the tool is made and its area of ​​application.

HSS-R(or simply HSS) - designation on products that have been rolled and heat treated. Such products have the lowest durability.

HSS-G- designation on products made of HSS steels, the cutting part is ground with CBN (cubic boron nitride). Products have increased durability and less radial runout. HSS-G tools are the most common, they are used to solve common tasks.

HSS-E- cobalt is added to products made of HSS steel of the M35 type. It is used when working on viscous and complex materials. There are also such markings as HSS Co 5 and HSS Co 8, which indicate the content of cobalt 5 and 8%

HSS-G TiN- such marking indicates the deposition of titanium nitride. This coating allows to increase the surface hardness by approximately 2300 HV and heat resistance up to 600 ° C.

HSS-G TiAlN- the surface of products with titanium-aluminum-nitride sputtering. This coating allows to increase the surface hardness by approximately 3000 HV and heat resistance up to 900 ° C.

HSS-E VAP - VAP-used for processing stainless steels (V2A and V4A). It is obtained by "evaporation" of the oxide non-metallic layer. This reduces the adhesion of workpiece chips to the surface of the tool, which can lead to product breakage. The result is improved surface quality and, thanks to VAP, the adhesion of the coolant to the tool surface is improved.

Characteristics of heat resistance of carbon and redness of high-speed tool steels
steel grade	Tempering temperature, ° C	Exposure time, hour	Hardness, HRC eh
U7, U8, U10, U12	150-160	1	63
P9	580	4
U7, U8, U10, U12	200-220	1	59
R6M5, R6M5K5, R9, R9M4K8, R18	620-630	4

and1111 15-12-2009 19:12

hello community! here, I got a piece of a knife from a jointer from this one. I know that high-speed steel with tungsten, but whether it is suitable for a blade, whether it is possible to weld a tail to it, how, whether it rusts strongly, I don’t know anything. I tried to ask the sergeant via a personal note, because there are enough topics about metal here, but the hanza is in my repertoire ...

AAAAA 15-12-2009 19:26

p18. I really liked the wedge from this. as well as an amateur.

Borz87 15-12-2009 19:44

Yesterday I saw it in the store too, I think I should take it, don't take it, a short 200mm costs 400 rubles, a meter long one is more tyshy, and people sometimes use the fast rubber, the cutters have finished it, you will spend half a day until you carve a strip out of it ..
there by the way hardening is not zone, I hope?

Udod 15-12-2009 20:15

In my childhood, a blade from P18 split into three parts (although it was thrown into the fence.) And in my student years, a friend of a hike from the cutting edge chipped out several pieces. In general, the most fragile of all quick cuts, but cuts well.

and1111 15-12-2009 20:52

yeah. suitable. I am not going to throw and cut, it is hardened entirely. I have long wanted to make a knife for dear Andrey Vasilich out of good carbon, I'm tired of stainless soap. I want to - whack! and the tail will not bounce off the welding? or do you need to warm it up beforehand? can you re-harden it?

sheb 15-12-2009 21:08

And why did you decide that this is P18? For example, I have "FABA" knives on my machine, it also says HSS18% W, they plan well, but I tried a super soap cut for a knife, threw it in the trash.

Knife maker 15-12-2009 21:09

I have been working with P18 for over a year.
Excellent steel !! But I forge it on blades from the 18mm square.

Weld the tail ?! I will not say anything, because I have not tried it!

Overheat? There, the temperature is needed about 1250-1280C. Without experience and experiments, nothing good will come of it.

And so, you can fix it from a plane knife. But nothing special should be expected.

dblsav 15-12-2009 21:49

I made a knife out of this steel. I will not say that the cut is excellent, but I also will not say that it is super soapy. "Boys' tests" with reasons of 0 will not stand, it will crumble. Fishing ten-day knife plowed honestly. There is an opinion that it is necessary to sharpen knives from this steel not as usual, but without polishing the RK.
Good luck.

sheb 15-12-2009 22:02

quote: There is an opinion that it is necessary to sharpen knives from this steel not as usual, but without polishing the RK.

Like that there was not a microsaw, but a macro?

dblsav 15-12-2009 22:10

quote: Originally posted by sheb:
Like that there was not a microsaw, but a macro?

"Like yes" .... diamond 20-40 microns and good.

boroda-fish 16-12-2009 12:21

quote: "Like yes" .... diamond 20-40 microns and good.

I join, for some reason, on P18 and P9, the amendment after the diamond "20-ki" is "five" - ​​it breaks better, but it doesn't look childish ...
why is it considered that HSS 18% W is p18?

------------------
Best regards, Bearded Fish

anatoly 16-12-2009 04:32

quote: why is it considered that HSS 18% W is p18?

Because P18 also contains 18% tungsten. I made a knife out of it, there is still a piece at home. Didn't cause admiration, but nothing at all. Made zero runs at 4 cm wide and 3 mm thick. Do not fade. Res so-so. It quickly loses its razor sharpness, but on the residual it cuts for a long time. As they say - "he cuts well, but cuts not very well." Weld that either simply does not work. It is better to cut it out under the dovetail, or make a cut with a grinder and rivet the hairpin.
Sincerely

December 16-12-2009 12:58

If the knife is from a jointer, then it is 8x6nft, steel on the knife is better than you can imagine. It rusts weakly, hardness 56-58, is not afraid of burns on emery (within reasonable limits), sharpens easily, cuts great, can be welded.

chief 16-12-2009 13:03

I'm not too lazy to write everywhere - it's easier for me to solder a tail with silver or brass than to cook it, because it's at home, in the kitchen ...

GAU-8A 16-12-2009 13:24

You can weld everything with argon, stainless steel shanks were welded to 90V, to Jap.CV134, to Petrikov metal ceramics.

sm special 16-12-2009 13:37

quote: Originally posted by and1111:
..., is it possible to weld a tail to it than, ...

From "Grade of steels and alloys" о Р18: weldability - good in butt electric welding with steels 45 and 40X.
From theory: P18 has a very heterogeneous structure and is significantly inferior to P3M5 in terms of quality indicators.

and1111 16-12-2009 14:48

I tried it on emery: rare little dark sparks.

anatoly 16-12-2009 17:33

quote: If the knife is from a jointer, then it is 8x6nft

But there is no 18% tungsten.

It is brewed well when tempered, and when hardened, for some reason it does not want to. At least our welders could not weld. It seems that the welders are not bad either. Tears it after welding and in akurat along the seam. It may be necessary to heat the seam, or to slowly cool down. Well, in general, it didn't work out for us then.

Threat 18% of tungsten is not so easy to cram into any composition. In general, it should be analogous to P18, but if you looked at the vintage, then there jumps up to 0.2 percent in carbon, chrome - up to 1, etc. and all this is within the limits of GOST, so that there is probably no need to talk about an analogue even from smelting to smelting. Then I noticed that a fast cutter cuts better at lower hardness (in the region of 50-55) (My IMHO), at 57-58 - namely, this hardness of knives for woodworking, it cuts worse. All imha, of course.
Sincerely

and1111 16-12-2009 19:54

here is Comrade. the sergeant is an amateur quick-cutter, but he is keeping something neutral. but he knows exactly what this piece of iron can do. Well, so that you do not vomit during welding, you must first heat it up with gas. I only need to lengthen the tail, the blade will not suffer.

2018-05-25

HSS drills are drills made from High Speed ​​Steel. It also goes to production:

1. dies;
2. taps;
3. cutters;
4. and other tools for metalworking.

Photo # 1: HSS drills

In this article, we will introduce HSS drills in detail. After examining the information, you can easily select and buy the necessary tools in the store.

How HSS drills differ from carbide models

First of all, HSS drills differ from carbide drills in material technology.

High-speed steel is produced by adding tungsten, chromium, molybdenum and other components to carbon steel. The material of HSS drills has high strength.

1. Carbide is composite material made by powder metallurgy technology.It consists of micron-sized particles. The main component is tungsten carbide. Additional include titanium carbide, tantalum carbide, etc.

Solid carbide tools from HSS drills are characterized by higher hardness and heat resistance. However, carbide alloys have lower strength. They are afraid of vibrations and power loads. This prevents carbide drills from being used for intermittent cutting of workpieces at high speeds.

Due to the complex manufacturing technology, carbide tools are expensive. from high speed steel is much lower.

Marking of HSS drills, their types and domestic counterparts

All HSS drills are marked accordingly. There are three varieties of this steel.

Tungsten (T1 – T15).

1. Molybdenum (M1 – M36).

2. Highly alloyed (M41 – M62).

Tungsten HSS Drills

From this group, the most widespread are drills made of four types of steels.

T1 (domestic analogue - P18). This HSS steel (18% tungsten) with high characteristics (grindability, strength and wear resistance) is used to make drills and other general-purpose tools. They are best suited for machining carbon and alloy structural steels.

1. T2 (domestic analogue - R18F2). The alloy contains 2% vanadium. It is used for the manufacture of finishing and semi-finishing drills intended for processing medium alloy structural steels.

2. T3 (domestic analogue - Р18K5Ф2). The alloy contains 18% tungsten, 5% cobalt and 2% vanadium. Such tools are characterized by increased secondary hardness and wear resistance, but have low grindability. This type of drill is best suited for machining workpieces made of high-strength, corrosion-resistant and heat-resistant steels and alloys.

3. T15 (domestic analogue - R12F5K5). This marking on HSS drills means that in addition to 12% tungsten, vanadium (5%) and cobalt (5%) have been added to the alloy. These tools are distinguished by their high strength, toughness and wear resistance. They are used when drilling difficult-to-machine materials.

Image # 1: composition of tungsten HSS steels

Molybdenum HSS Drills

The main alloying component of steels in this group is molybdenum. Also in different quantities may contain:

tungsten,

1. cobalt;

2. vanadium;

3. carbon;

4. and other components .

Image # 2: composition of molybdenum HSS steels

The most widely used are HSS drills made from the following types of molybdenum high speed steels.

M1. From steel of this grade (8% molybdenum), general-purpose tools are produced. These HSS drills are highly flexible and shock resistant. Redness is lower than that of analogues.

1. M2 (domestic analogue - Р6М5). It is the most common material for the production of HSS drills. The alloy contains 6% tungsten and 5% molybdenum. It has balanced strength, hardness and heat resistance.

2. M3 (domestic analogue - Р6М5Ф3). This alloy also contains 3% vanadium. HSS drills made from this steel are characterized by lower abrasive wear.

3. M7. The main alloying components are molybdenum (8.75%), vanadium (2%) and tungsten (1.75%). Drills made from this HSS steel are used for drilling in hard and heavy metal.

4. M35 (domestic analogue - Р6М5К5). In addition to tungsten, molybdenum and vanadium, this alloy contains cobalt (5%), as well as small amounts of manganese, silicon and nickel. The advantages of this material are good toughness, excellent grindability, heat and wear resistance. HSS drills made from this alloy are used when machining workpieces from improved alloy and stainless steels in conditions of increased heating of the cutting edge.

High alloy HSS drills

For the production of high-alloy HSS-drills (with high impact toughness and operated in cold conditions), molybdenum alloys are used, which are subjected to a special heat treatment.

Image # 3: composition of high alloyed HSS steels

M47 (domestic analogue - Р2АМ9К5). It contains large quantities of molybdenum (9%) and cobalt (4.7–5.2%). The alloy has an increased tendency to decarburization and overheating during quenching. Grindability - low. HSS drills made from this alloy are used for machining workpieces made from improved alloy and stainless steels.

1. M42. Contains a large amount of cobalt and molybdenum (8 and 9.5%, respectively). HSS drills made from this alloy are characterized by increased redness and abrasion resistance. Such tools are used in the processing of viscous and complex metals.

Foreign marking of HSS drills

As we noted above, the HSS marking means that the drill for metal is made of high speed steel. Foreign tool manufacturers add various additional designations that indicate the technologies used and other features. Let's talk about the markings of common HSS drills.

The following factors directly influence the choice of HSS drills.

The grade of the processed steel. The choice of tool for the material of manufacture depends on it.

1. Equipment to be equipped with a drill. Buy drills with shanks that match the equipment available.

2. Frequency of use. If you are looking for a HSS drill for a one-off job, the inexpensive models are fine. If you use the tool often, do not skimp on quality.

Detailed information on the selection of metal drills for various works you will find in this article (put a link to the page with article # 1).

HSS (High Speed ​​Steel)- it general definition groups of high-speed steels. HSS steel is used for the manufacture of a large number of different cutting tools. Usually, these are drills, taps, cutters…. HSS steels are high carbon and some contain a high proportion of tungsten. Typically, HSS steel tools have a hardness of 62-64 HRC. The main advantages over carbide tools are durability and lower tool cost. Therefore, HSS performs well in interrupted cuts. The limitation of HSS applications is the low cutting speeds compared to cemented carbides.

Abroad, as well as in our country, at the end of the 19th century, HSS steels with a high tungsten content (18%) were first used. The first record of the use of cobalt in steels appeared in Germany in 1912. Later, in 1930, molybdenum was introduced to the United States.

Characteristics of HSS steels

HSS has come to be divided into three groups:

• Tungsten (T);
• Molybdenum (M);
• High-alloy high-speed steels.

Tungsten steels are practically not used today due to the high cost of tungsten and its shortage. The most common are general-purpose steel T1 and steel with vanadium and cobalt T15. T15 are used for tools operating in high temperature and wear conditions.

Molybdenum steels have molybdenum as the main alloying element, although some contain equal or even more tungsten and cobalt. Steels with a high vanadium and carbon content are resistant to abrasion. A series of steels starting from M41 is characterized by high hardness at high temperatures (redness). Molybdenum steels are also used in the manufacture of tools operating in "cold" conditions - rolling dies, cut-out dies. In such cases, HSS steels are hardened to lower temperatures to increase toughness.

HSS (High Speed ​​Steel)- the designation HSS stands for "high speed steel".

Steel with a hardness of 62-65 HRC. Compared to HCS (high carbon steel), the metal thickness of HSS is less, and the hardness is much higher, generally applicable to the entire class of high-speed steels. But in most cases, this is the designation for the most massive HSS steel of the P6M5 class (M-2; 1.3343; Z85WDCV; HS 6-5-2; F-5613). High speed steel average productivity, in terms of toughness, it is suitable for drills for metal, milling cutters of smaller diameters and processing materials up to a strength of 900 MPa, for working on materials such as metal, aluminum and non-ferrous metals.

HSSE(general designation for the group of high-speed steels with cobalt content, which includes HSS-E, HSS-Co5, HSS-Co8) - tool high-speed steel, analogous to Р6М5К5.

Steel with a hardness of 63-67 HRC, anti-corrosion and acid-resistant steel, high-performance high-speed steel with good toughness, suitable primarily for tools of larger diameters and disc milling cutters, for work on cast iron, aluminum, aluminum alloys, copper, brass and bronze.

HSS-G (analogue Р6М5)-This designation is applied to drills, the cutting part of which is ground with borazon (CBN). HSS G tools are the most common ones and are characterized by increased durability. In addition, a drill for metal, on which this designation is applied, creates the least runout when performing processing with it.

Steel with a hardness of 62-65 HRC. Grinding drills are better than rolling HSS tools.

Application: steel, alloy steel and cast carbon steel (strength; up to 900 N / mm2), gray, malleable cast iron, cast iron with spheroidal graphite precipitates, die-cast steel, cupronickel, graphite, aluminum alloys, brass and bronze.

HSS-G TiN- high-speed tool steel, titanium-nitride coating.

Thanks to this coating (TiN), which protects the tool from wear, the surface hardness increases by about 2300 HV, and the heat resistance; up to 600 ° C.

Application: carbon and alloy steel (with strength up to 1200 N / mm2), alloy steel with a high chromium content, as well as steel V2A, V4A, anti-corrosion and acid-resistant steel. Designed for processing steel, bronze, copper-nickel alloys, graphite, titanium, titanium alloys, cast iron, aluminum, aluminum alloys, copper, brass. Titanium sputtering reduces overheating and improves chip evacuation.

HSS-G TiAlN- high-speed tool steel, titanium-aluminum-nitride coating, G (Grinding); polished.

Thanks to this coating (TiAlN), which protects the tool from wear, the surface hardness increases by about 2300 HV, and the heat resistance; up to 600 ° C

Application: carbon and alloy steel (with strength up to 1200 N / mm2), alloy steel with a high chromium content, as well as steel V2A, V4A, anti-corrosion and acid-resistant steel, titanium, titanium alloys, cast iron, aluminum, aluminum alloys, copper, brass and bronze.

HSS-Co 5%

Other designation options: HSCO, Co5%, S 6-5-2-5, 1.3243, Z 90 WDCV 06-05-04-02, HS 6-5-2-5, BM 35. Steel with good material handling toughness up to strength 1200 MPa. According to its properties, HSS-Co5% steel is between P6M5K5 and P9 (closer to P9), which will make it possible to recommend it as a replacement for P9.

HSS-Co 8%- high-performance high-speed steel with a high cobalt content.

Steel with a hardness of 63-68HRC, other designations: Co8, Co 8%, S 2-10-1-8, Z 110 DKCWv 09-08-04-02-01, HS 2-9-1-8, BM 42 , M42. According to its properties, 8% HSS-Co steel is between P6M5K5 and P18 (closer to P18), which will make it possible to recommend it as a replacement for P18. The high content of cobalt contributes to an increase in redness, which allows you to set more severe cutting conditions. High performance steel with good toughness and excellent heat resistance. Especially suitable for milling high-strength materials, austenitic steel, steels for hot forming (hot forming), etc.

HSSE-PM- high-performance high-speed steel.

The steel is obtained by powder metallurgy methods. The steel has a homogeneous structure, which is manifested by a higher dimensional resistance and tool cutting edge resistance. Suitable for machining high-strength and difficult-to-machine materials such as titanium and titanium alloys. Cutters made of this steel are supplied with AlTiN coating as standard.

The abbreviation HSS, made up of the initial letters of the English words High Speed ​​Steel, denotes a whole group of steels belonging to the high-speed category. Cutters, taps, dies for threading are made from steels of this type. Much less often, such material is used for the production of hacksaw blades and knives.

Alloys of the HSS category belong to, in some grades of which a significant amount of tungsten can be contained. The hardness of a tool made of this type of steel can be in the range of 62–64 HRC units.

End mill made of HSS-Co8 steel is capable of machining material with tensile strength up to 1100N / mm 2

Tools made from HSS steels, when compared to carbide, are more affordable and stronger, which makes them successfully used for interrupted cuts. Meanwhile, processing with their help is allowed for more low speeds cutting versus carbide drills.

The composition, which foreign manufacturers call HSS alloys, has been constantly improved. So, from the end of the 19th century, a significant amount of tungsten (up to 18%) began to be added to such steels, and from 1912 cobalt began to appear in these alloys. It was only in 1930 that molybdenum was included in HSS steels.

Main characteristics and brands

Depending on their composition, HSS steels are divided into three categories:

• with a high content of tungsten (T);
• molybdenum (M);
• highly alloyed group.

Due to the high cost and shortage of tungsten, steel with its high content is rarely used nowadays. The most common steels in this group are the T1 general purpose alloy and the T15 steel alloy containing vanadium and cobalt. The latter is used, in particular, for the manufacture of products that must be highly resistant to wear and high temperatures.

More common are HSS steels of the molybdenum group, which can also contain tungsten and cobalt. High-speed steels of the molybdenum group, which contain a significant amount of vanadium and carbon, are resistant to abrasive wear. For the manufacture of products that must maintain high hardness even at high temperatures, molybdenum steel alloys are used, starting from the M41 brand. Steel alloys of the molybdenum group are also used in the production of tools that operate in cold conditions and have a high impact strength, subjecting them to a special heat treatment.

When choosing tools from molybdenum HSS steels, the characteristics of individual grades of such steel alloys should be taken into account.

M1

HSS drills of wide application are made of this steel grade. HSS drills made from M1 grade are more flexible and less susceptible to shock loads, but their level of redness is less than that of tools made of M2 steel.

M2

This is the most common material from which tools for various purposes are made. Products made of HSS-steel of this brand, used for high-performance machine work, are distinguished by high redness resistance, the parameters of their cutting edges remain longer than that of tools made of high-speed steels of other brands.

M7

This grade is used for the production of heavy-duty drills, which require not only high flexibility but also exceptional reliability. With the help of HSS metal drills made of this alloy, holes are made in hard and heavy plate material.

M50

It is a material used to make drills that work with portable equipment. Under these conditions, tool breakage due to its significant bending is a rather urgent problem. The M50 steel alloy HSS drill does not have the same resistance to redness as other high speed steel tools.

M35

This alloy, which is also referred to as HSSE, due to the increased content of cobalt, has a higher redness resistance than high-speed steel grade M2. Meanwhile, the increased content of this element in the composition of HSSE steel reduces its resistance to shock loads.

M42

It is a steel that contains maximum amount cobalt, which is why it is often called Super Cobalt. Tools made of HSS steel of this brand are distinguished not only by their high redness resistance, but also by their exceptional abrasion resistance. Due to these characteristics, steel of this grade is successfully used for the production of tools with which it is necessary to process viscous and complex materials.

The content of tungsten in the composition of HSS steels allows endowing the products that are made of them with red resistance.

This quality lies in the fact that the cutting edge of the tool retains its hardness even at a red heat temperature of 530 °. High-speed steel alloys, which contain cobalt (HSS Co), have an even higher resistance to redness (as well as increased wear resistance). The cutting edges of HSS Co category drills are able to maintain their hardness at higher temperatures.

Symbols

Deciphering the chemical composition of steels belonging to the HSS category is difficult, since their designation does not contain any detailed data. As a rule, catalogs for tools made from steels of this category contain information about the materials for which it can be used. To relatively accurately determine the chemical composition of HSS steels, it is necessary to use special equipment or to solve this issue empirically.

It is better to understand the characteristics and material of manufacture of the tool on which the HSS marking is applied, the knowledge of the following data helps.

HSS

The letter R is often added to this abbreviation. These are the drills with the least durability. They are rolled and heat treated.

HSS G

This designation is applied to drills, the cutting part of which is ground with borazon (CBN). HSS G tools are the most common ones and are characterized by increased durability. In addition, a drill for metal, on which this designation is applied, creates the least runout when performing processing with it.

HSS with letter E

This designation indicates that the composition of the material of manufacture of the product contains cobalt. The HSSE designation tool is ideal for tough materials as well as high toughness materials. As mentioned above, the analogue of the HSSE designation is the M35 marking. There are also international analogues of the HSSE designation (HSS-Co5 and HSS-Co8), which can be used to determine exactly how much cobalt is contained in the steel alloy.