About high-speed steel for drill/taps you need to know
- What is high-speed steel?
- How many main types of HSS and their character, cost
- The Top brand in China of HSS, their character, and cost
- The meaning of knowing China HSS — Decide how to choose the tools supplier.
High-speed steel is a kind of high alloy steel containing many carbons (C), tungsten (W), molybdenum (Mo), chromium (Cr), vanadium (V), and other elements. When the cutting temperature is up to 600℃ above, the hardness is still not significantly decreased, the cutting speed of the tool can reach more than 60 meters per minute. So that’s why called high-speed steel. It is widely used in all kinds of cutting tools and tools, including turning tools, milling cutters, drills, and saw blades.
Then how many types of HSS and what about their character and cost?
According to the performance, the high-speed steel can be divided into Low alloy high-speed steel（HSS-L), Normal high-speed steel（HSS), and high-performance high-speed steel（HSS-E).
For these three-level HSS, there is some common grade:
HSS-L W4Mo3Cr4VSi(4341), W2Mo1Cr4VSI(4241)
HSS W6Mo5Cr4V2, W9Mo3Cr4V
HSS-E W6Mo5Cr4V3, W6Mo5Cr4VCo5, W2Mo9Cr4VCo8
W: Improve the red hardness and high wear resistance of steel
Mo: Improve the tenacity, Reduce the thermal conductivity, as well as the freezing point of steel;
Cr: Increase the hardenability, oxidation resistance, decarbonization and corrosion resistance of high-speed steel;
V: Improve the hardness and wear resistance of the steel under high temperatures.
Co: Improve high-temperature hardness, secondary hardness and thermal conductivity of HSS
According to the alloying element’s function, so we could know the above hss’s characters.
Red hardness/Wear resistance
For the past, the cost of W9Mo3Cr4V is lower than W6Mo5Cr4V2, as the cost of W increasing, now the prices of W9Mo3Cr4V is a little higher than M2.
Based on the above information, normally different grade hss has a different use:
1、4241/4341 material: This material is suitable for drilling ordinary metals, such as iron, copper, aluminum alloy, and other low and medium hardness metal, as well as wood, plastic, etc. Not suitable for drilling stainless steel, mold steel, and other high strength, high hardness metal. Within the scope of application, the quality is not bad, suitable for wholesale sales at hardware stores.
2、9341/6542 material: This material is suitable for drilling various metals, such as stainless steel, iron, copper, aluminum alloy, and other low and medium hardness metals. Medium to high quality with good durability in the range of application.
3, 6543, with a vanadium content of 3-4%, much higher wear resistance but will reduce the grinding efficiency, suitable for the manufacture of threaded tools.
5、M35 cobalt material: This material is the best performance grade of high-speed steel in the market at present, the cobalt content ensures the hardness and toughness of high-speed steel. Suitable for drilling various metals, such as stainless steel, iron, copper, aluminum alloy, cast iron, 45# steel, and other metals.
6、M42：Vanadium content is not high (1%), cobalt content is high (8%), cobalt can make the carbide dissolve more in the matrix when quenching and heating, use the high matrix hardness to improve wear resistance. This high-speed steel has excellent hardness, thermal stiffness, abrasion resistance, and wearability. Heat treatment hardness up to 67-70HRC, but there are also special heat treatment methods to get 66-68HRC hardness so that its cutting performance (especially intermittent cutting) to improve the impact toughness. Cobalt HSS can be made into a wide range of tools and is used to cut difficult materials with good results. When the cutting temperature reaches 600°C or more, there is no significant reduction in hardness, and the cutting speed of the tool made with it can reach more than 60 m per minute.
The red hardness, wear-resistance and tenacity decide the hss cutting tools performance. So we could choose the material according to the cost, the workpiece, and working environment.
The current brand in China for HSS has HEYE, TIANGONG, FEIDA, FUDA, JINGGONG, FUGONG, etc, based on their melting technology, developing and research ability, and brand’s popularity. Also as our know and use for them.
Performance Stability( Uniformity, purity)
When we evaluate the stability of the hss, it’s hard to judge who is better only from 1 or 2 batches. As a customer of HEYE and tiangong so many years, also the market feedback, the stability of heye is better than Tiangong
When we know the characteristics of the aforementioned HSS in comparison to several domestic brands, then we know how to choose the tool suppliers based on our quality requirement and company position in the market.