Commonly used steel grades and performance characteristics

45 – High-quality carbon structural steel, the most commonly used medium-carbon quenched and tempered steel.

Main characteristics: The most commonly used medium-carbon quenched and tempered steel, with good comprehensive mechanical properties, low hardenability, and prone to cracking during water quenching. Small parts are suitable for quenching and tempering, while large parts are suitable for normalizing. Applications: Mainly used for manufacturing high-strength moving parts, such as turbine impellers, compressor pistons, shafts, gears, racks, and worm gears. For welded parts, preheating before welding and stress-relieving annealing after welding are important.

Q235A (A3 steel) – The most commonly used carbon structural steel.

Main characteristics: High plasticity, toughness, weldability, cold stamping performance, and certain strength and good cold bending performance. Applications: Widely used for parts with general requirements and welded structures, such as tie rods, connecting rods, pins, shafts, screws, nuts, collars, brackets, machine bases, building structures, and bridges.

40Cr – One of the most widely used steel grades, belonging to alloy structural steel.

Main characteristics: After quenching and tempering, it possesses good comprehensive mechanical properties, low-temperature impact toughness, and low notch sensitivity. It has good hardenability, and high fatigue strength can be obtained when oil-cooled. However, water cooling can easily cause cracks in complex-shaped parts. It has moderate cold bending plasticity, and good machinability after tempering or quenching and tempering, but poor weldability and susceptibility to cracking. Preheating to 100℃～150℃ is required before welding. It is generally used in the quenched and tempered state, but it can also undergo carbonitriding and high-frequency surface hardening treatments.

Examples of applications: After tempering, it is used to manufacture medium-speed, medium-load parts, such as machine tool gears, shafts, worm gears, splined shafts, and ejector pin sleeves. After tempering and high-frequency surface hardening, it is used to manufacture parts with high surface hardness and wear resistance, such as gears, shafts, spindles, crankshafts, mandrels, sleeves, pins, connecting rods, screws, nuts, and intake valves. After quenching and medium-temperature tempering, it is used to manufacture heavy-load, medium-speed impact parts, such as oil pump rotors, sliders, gears, spindles, and collars. After quenching and low-temperature tempering, it is used to manufacture heavy-load, low-impact, wear-resistant parts, such as worm gears, spindles, shafts, and collars. Carbonitriding is used to manufacture larger transmission parts with high low-temperature impact toughness, such as shafts and gears.

HT150—Gray Cast Iron

Examples of applications: Gearbox housings, machine tool beds, housings, hydraulic cylinders, pump bodies, valve bodies, flywheels, cylinder heads, pulleys, and bearing covers.

HT150—Gray Cast Iron

Examples of applications: Gearbox housings, machine tool beds, housings, hydraulic cylinders, pump bodies, valve bodies, flywheels, cylinder heads, pulleys, and bearing covers. 35 – Commonly used material for various standard parts and fasteners

Main characteristics: Suitable strength, good plasticity, high cold plasticity, and fair weldability. Can be locally upsetting and wire drawing in the cold state. Low hardenability; used after normalizing or tempering. Applications: Suitable for manufacturing small cross-section parts and parts that can withstand large loads, such as crankshafts, levers, connecting rods, and hooks, as well as various standard parts and fasteners.

65Mn – Commonly used spring steel

Applications: Various small-sized flat and round springs, seat springs, and spring clockwork; also used to make spring rings, valve springs, clutch springs, brake springs, cold-coiled coil springs, and retaining rings, etc.

0Cr18Ni9 – The most commonly used stainless steel (US grade 304, Japanese grade SUS304)

Properties and Applications: Widely used as a stainless heat-resistant steel, such as in food processing equipment, general chemical equipment, and energy industry equipment.

Cr12 – A commonly used cold work die steel (US grade D3, Japanese grade SKD1)

Properties and Applications: Cr12 steel is a widely used cold work die steel, belonging to the high-carbon, high-chromium type of ledeburitic steel. This steel has good hardenability and good wear resistance; however, due to its high carbon content (2.3%), Cr12 steel has poor impact toughness, is prone to brittle fracture, and easily forms uneven eutectic carbides; due to its good wear resistance, Cr12 steel is often used to manufacture cold stamping dies, punches, blanking dies, cold heading dies, cold extrusion dies, punches and dies, drill bushings, gauges, wire drawing dies, embossing dies, thread rolling dies, deep drawing dies, and cold pressing dies for powder metallurgy, etc., which require high wear resistance under relatively low impact loads.

DC53 – Commonly Imported Japanese Cold Work Die Steel

Characteristics and Applications: High-strength and high-toughness cold work die steel, manufactured by Daido Steel Co., Ltd., Japan. After high-temperature tempering, it exhibits high hardness and high toughness, with good wire cutting properties. Used for precision cold stamping dies, drawing dies, thread rolling dies, cold blanking dies, punches, etc.

SM45 – Ordinary Carbon Plastic Mold Steel (Japanese steel grade S45C)

DCCr12MoV – Wear-Resistant Chromium Steel (Domestic)

Lower carbon content than Cr12 steel, with the addition of Mo and V, improving carbide uniformity. Mo reduces carbide segregation and improves hardenability, while V refines grains and increases toughness. This steel has high hardenability; sections below 400mm can be fully hardened. It maintains good hardness and wear resistance at 300℃~400℃, has higher toughness than Cr12, minimal volume change during quenching, and high wear resistance and good overall mechanical properties.

Therefore, it can be used to manufacture various molds with large cross-sections, complex shapes, and subjected to significant impacts. Examples include general drawing dies, punching dies, blanking dies, trimming dies, hemming dies, wire drawing dies, cold extrusion dies, cold cutting shears, circular saws, standard tools, and measuring instruments.

SKD11 – Tough Chromium Steel (manufactured by Hitachi, Japan)

Technically improved casting structure, refined grains, resulting in increased toughness and wear resistance compared to Cr12MoV, extending the service life of dies.

D2 – High Carbon High Chromium Cold Work Steel (Made in the USA)

High hardenability, hardenability, and wear resistance, with good high-temperature oxidation resistance. Good rust resistance after quenching and polishing, and minimal deformation after heat treatment. Suitable for manufacturing various cold work dies, tools, and measuring instruments requiring high precision and long service life. Examples include drawing dies, cold extrusion dies, and cold shearing blades.

SKD11 (SLD) – Non-Deformable Tough High Chromium Steel (manufactured by Hitachi, Japan)

Due to increased Mo and V content, improved casting structure, refined grains, and improved carbide morphology. Therefore, this steel has higher strength and toughness (bending strength, deflection, and impact toughness, etc.) than SKD1 and D2, increased wear resistance, and higher tempering resistance. Practical experience has shown that this steel improves the lifespan of dies compared to Cr12mov. It is commonly used to manufacture high-requirement dies, such as drawing dies and impact grinding wheel dies.

DC53—High-toughness high-chromium steel (manufactured by Daido Steel, Japan)

Its heat-treated hardness is higher than SKD11, reaching 62-63 HRC after high-temperature tempering (520℃~530℃). DC53 surpasses SKD11 in strength and wear resistance. Its toughness is twice that of SKD11. The toughness of DC53 results in fewer cracks and fissures in cold-working die manufacturing, significantly improving service life. It has low residual stress, which is reduced by high-temperature tempering, suppressing cracks and deformation after wire EDM. Its machinability and grindability exceed SKD11, making it suitable for precision stamping dies, cold forging, and deep drawing dies.

SKH-9 – High-performance, wear-resistant, and tough general-purpose high-speed steel (manufactured by Hitachi, Japan).

Used in cold forging dies, cutting machines, drills, reamers, and punches.

ASP-23 – Powder metallurgy high-speed steel (made in Sweden).

Extremely uniform carbide distribution, wear-resistant, high toughness, easy to machine, and dimensionally stable after heat treatment. Used in punches, deep drawing dies, drill dies, milling cutters, and shearing inserts, and other long-life cutting tools.

P20 – General-purpose plastic molds (made in the USA).

Suitable for electro-erosion processing. Factory pre-hardened HB270~300, quenched hardness HRC52.

718 – High-performance plastic molds (made in Sweden).

Especially suitable for electro-erosion processing. Factory pre-hardened HB290~330. Quenched hardness HRC52.

Nak80 – High-precision, mirror-finish plastic molds (made by Daido Steel, Japan).

Factory pre-hardened HB370~400, quenched hardness HRC52. S136 – Corrosion-resistant and mirror-polished plastic molds (Sweden). Factory pre-hardened HB < 215, quenched hardness HRC 52.

H13 – Commonly used die-casting molds, used for aluminum, zinc, magnesium, and alloy die casting, hot stamping dies, and aluminum extrusion dies.

SKD61 – High-grade die-casting molds (Hitachi, Japan).

Utilizes electrolytic remelting technology, significantly improving service life compared to H13. Used for hot stamping dies and aluminum extrusion dies.

8407 – High-grade die-casting molds (Sweden).

Used for hot stamping dies and aluminum extrusion dies.

FDAC – Sulfur is added to enhance machinability.

Factory pre-hardened hardness 338~42 HRC, allowing direct engraving without quenching or tempering. Used for small-batch molds, simple molds, various resin products, sliding parts, mold parts with short lead times, zipper molds, and eyeglass frame molds.