AISI 1095 is high carbon steel with high hardness and wear resistance. These steels are suitable for the production of various kinds of daggers and knives due to excellent edge retention and wear resistance. High carbon steel has a factor of brittleness due to strong cementite network in the matrix but it does not prevent it from being the best knife steel. Carbon steel is prone to rust that’s why variant called 1095 cro-van steel is used for dagger making due to excellent corrosion resistance.
In the below discussion, 1095 steel properties, heat treatment, metalworking are discussed. Also, we have to share our insight on cro-van 1095 steel. The comparison of this grade of steel with other steel has also been made to facilitate you in the selection of blade steel.
|AMS 5121||ASTM A29 (1095)||ASTM A713 (1095)||MIL S-7947|
|AMS 5122||ASTM A510 (1095)||ASTM A830||MIL S-8559|
|AMS 5132||ASTM A576 (1095)||DIN 1.1274||QQ S700 (C1095)|
|AMS 7304||ASTM A682 (1095)||MIL S-16788 (C10)||SAE J1397 (1095)|
|AMS 5132D||SAE J403 (1095)||SAE J412 (1095)||AMS 5121C|
1095 carbon steel Composition
|Elements||1095 plain steel||1095 cro-van steel|
|C||0.90 - 1.03||0.90 - 1.03|
|Mn||0.30 - 0.50||0.25-0.45|
|S||< 0.050||< 0.025|
|P||< 0.040||< 0.025|
1095 carbon steel properties
|Melting Point||1530 C|
For hardness test, you can review;
|Yield Strength||525 Mpa|
|Elastic Modulus||205 GPa|
|Hardness (Rockwell C)||13|
|Machinability (Based on AISI 1212 steel as 100 mahinability)||0.45|
|Elongation at break||0.1|
|Reduction of Area||0.4|
The mechanical properties given above are for spherodized steel for enhancing machinability. To view properties of this high carbon steel in state of forging, quenching and normalizing, Follow the links below;
- Oil quenched from 800°C (1475°F), tempered at 480°C (900°F) – (Link)
- As rolled – (Link)
- Annealed at 790°C (1450°F) – (Link)
- Oil quenched from 800°C (1475°F), tempered at 540°C (1000°F) – (Link)
- Oil quenched from 815°C (1500°F), tempered at 480°C (900°F) – (Link)
|Thermal Conductivity (W/m. K)||49.8|
|Specific Heat Capacity||0.461 J/g - C|
|W1 steel||CTE Liner (µm/m - C)|
|W1 Steel||Electrical resistivity (ohm - cm)|
1095 steel Forging
For knife production, the two most common methods used are material removal and forging. Forging involves heating and beating the steel to reduce the cross-section and shape into the semifinished product while improving the mechanical properties.
In advanced processes, knives are edge quenched to achieve higher hardness or brittleness in edge region only leaving the rest of blades tougher compared to the edge. This gives the blade ability to withstand the impact and shock loading and resistance to breaking.
Recommended Forging temperature for high carbon steel is 955oC to 1177oC.
This high carbon steel usually has a cementite network in its matrix. If annealing of steel is performed in a temperature range higher than 910oC, it could lead to a very brittle microstructure. The annealing in the austenite region is termed as Full – annealing. You can study the effect of full annealing microstructure on high carbon steel properties in the Annealing section.
Annealing used for high carbon steel is inter-critical annealing to avoid the development of continuous cementite networks upon cooling. This can be further studied in the Annealing microstructure section.
Annealing temperature chosen for 1095 high carbon steel is in between 810oC and 890oC.
Normalizing temperature for high carbon steel is the same as annealing temperature. In normalizing steel cementite network can be avoided to a much larger extent giving finer microstructure with less brittleness.
The comparison of normalized and annealed microstructure properties can be seen below;
|Tensile Strength (MPa)||965||1015||615|
|Yield Strength (MPa)||585||525||380|
|Reduction in Area %||0.17||0.21||0.45|
|Izod Impact Strength (J)||7||7||7|
Hardening is a fast cooling process involves the conversion of cementite and pearlite into martensite and retained austenite.
The hardening process for steel depends upon heating temperature and quenching media. For 195 hardening treatment, temperature above A3 line and water quenching for smaller castings are preferred. For large castings, oil quenching is preferred to avoid quench cracks which can be found in heat treatment defects.
Tempering 1095 steel
The development of martensite in structure results in large thermal stresses within material along with retained austenite formation. No quenching process can completely remove retained austenite. The reason can be studied in the TTT diagram in steel.
This retained austenite and martensite is converted to carbides to avoid brittleness and better machinability. Follow the Tempering steel process for stages which causes the conversion of retained austenite and martensite into carbides.
Tempering temperature for this steel is in between 372 and 705oC.
Welding of 1095
1095 has an interconnected matrix of cementite which is difficult to melt. That’s why this grade of steel is not preferable for welding.
1095 carbon steel Applications
Common Applications of plain carbon of steel of this grade are;
- Cutting Tools
- Grass Cutting tools
- Grain cutting tools
- Decorative swords
- Japanese Katana