Tool Steel Round Bar
Tool steel refers to a variety of carbon and alloy steels which are suited to be made into tools. Its suitability comes from the hardness, resistance to abrasion and deformation and the ability to hold a cutting edge at elevated temperatures.
Groups of Tool Steel
1) Water-hardening group –
This group is essentially plain high carbon steel. It is used because its cost is low. Here the high temperature are not encountered, above 150 degree Celsius. These tool steels can attain high hardness and are rather brittle compared to other tool steels.
2) Cold-work group –
This group has three tool steel that is oil-hardening, air-hardening and high carbon-chromium. The steels in the group has high hardenability and wear resistance with average toughness.
3) Shock-resisting group –
This group has high shock resistance and good hardenability. It is designed to resist shock at both low and high temperatures. This steel shows a very high impact on toughness and low abrasion resistance and can attain relatively high hardness.
4) High speed group –
T-type and M-type tool steels are used for cutting tools when strength and hardness must be retained at high temperatures. In room temperature it is basically a heat treatment and this grade shows high hardness.
5) Hot-working group –
This group develops to maintain strength and hardness. It is used to cut or shape material at high temperatures. These tool steels are low carbon and moderate to high alloy that provide good hot hardness and toughness and fair wear resistance.
6) Special purpose group/plastic mould steel –
P-type tool is short for plastic mould steels. Common steel grades like P20, 420 etc. L-type tool steel is short for low alloy special purpose tool steel. L6 is extremely tough. F-type tool steel is water hardened and substantially more wear resistant than W-type tool steel.
Types
1) Tungsten
2) Chromium
3) Vanadium
4) Molybdenum
Identification
It is identified as a tool maker. It is necessary for the tool maker to identify and classify tool steel.
1) High carbon/high chromium – high hardenability, secondary hardening steels.
2) Low alloy special purpose tool – L series. It is a water quench steels.
3) Mould tool steel – P series. Low carbon steels, high chrome moly and nickel.
4) Hot work tool steel – chromium hot work.
5) Hot work tool steel, hot work steel – molybdenum hot work. 0.60% carbon, 4% chrome, 1.0% vanadium, 15% tungsten, 5% moly.
6) Tungsten high-speed steel – 0.80% carbon (nominal), 4% chrome, 16.5% tungsten (nominal), 1% vanadium.
7) Molybdenum high-speed steel – 1% carbon (nominal), 4% chrome, 2% vanadium (nominal), 2% tungsten (nominal), 7% molybdenum (nominal).
Application
- Bushing
- Thread cutting
- Collets
- Die blanking
- Cold forming
- Cold trimming
- Drill bushing
- Gages
- Knurling tools
- Machine parts
- Setscrews
