High speed steels are complex iron-base alloys and may include some combination of carbon, chromium, vanadium, molybdenum and tungsten. Some of these are referred to as “Tungsten high speed steel”.
Many of the first types of high speed steel incorporated high tungsten content. Tungsten adds hardness and wear resistance to HSS alloys. In particular, it adds to hot hardness, causes secondary hardening and enhances resistance to tempering.
Types of Tungsten High Speed Steel
There are two major categories of HSS including tungsten, the T series and the M series. They have significantly different amounts of the element, changing their characteristics.
- T Type: T series alloys contain 12 to 20% tungsten as well as varying amounts of chromium, vanadium, carbon and cobalt. Some T series alloys do not include any carbon. PM T15 includes 5% cobalt, and has a unique combination of wear-resistance, impact toughness and bend strength. Compared to many other high speed tool steels, this alloy has impressive tool life. It is especially well-suited for cold work tooling.
- M Type: The M series alloys contain lower amounts of tungsten (between 1.25% and 10%). However, they make up for this in hardness by also include molybdenum. This element provides many of the same benefits as tungsten with a lower atomic weight. However, it has reduced hot hardness due to its lower melting point. The M series is often considered the go-to for most tooling applications. Some of these steels include M2, M3, M4, M7, and M42.
Additionally, other powdered metallurgy alloys that aren’t in the M series, including PM M4, PM A11, PM 23, PM 30, PM M48 and PM 60, all include some amount of molybdenum and tungsten.
Benefits of Tungsten HSS Steel
The principal benefit of tungsten HSS steel is that it offers excellent hot hardness. Some molybdenum high speed steels make up for its lower melting point by adding vanadium. However, tungsten can offer the same benefits without the need for additional vanadium content.
Another key advantage of tungsten steel is that it has excellent bend strength. Therefore, it is often more robust in cold work applications compared to high-carbon, high-chromium steels.
Tungsten-molybdenum steels are often viewed as the gold standard because they combine the hot hardness of the former with the low weight of the latter. This is very desirable in high speed tool steel.
High Speed Tool Steel
Griggs Steel has established a reputation among tool steel suppliers for its excellent high speed steel. It is our specialty. We are so confident in our HSS that we offer a guarantee that if it should ever fail due to a defect in the metal, we will credit the cost of the steel plus any work you have into the tools.
We have flats, rounds, block and plate, powdered metal sheet and more available in PM T15 and our M series alloys. If you need excellent-quality tungsten high speed tool steel, Grigg Steel is the first supplier you should contact.