T1 Tool Steel |1.3355 | S18-0-1

T1 Tool Steel |1.3355 | S18-0-1 Product Introduction

T1 tool steel (ASTM standard)

T1 steel is a tungsten-based high-speed tool steel (AISI standard) with a core composition of 17.25-18.25% tungsten, 0.65-0.80% carbon and 0.90-1.30% vanadium. Its characteristics include excellent red hardness (600 ℃ hardness to maintain ≥ 63 HRC) and high wear resistance, heat treatment needs to be 1270-1285 ℃ quenching and 550-570 ℃ double tempering, annealed hardness ≤ 255 HB. but carbide segregation tendency is significant, need to strictly control the forging temperature (1100-900 ℃) to optimise the organisation uniformity. -900℃) to optimise the organisation uniformity.

1.3355 tool steel (W-Nr/DIN standard)

1.3355 steel is a German DIN standard tungsten high-speed steel with a high degree of overlap in composition with T1 (tungsten 17.50-18.50%, carbon 0.70-0.78%, vanadium 1.00 -1.20%). Advantages include higher red hardness (66 HRC at 540°C) and a well-balanced wear-resistant-toughness combination, with a hardness of 62-65 HRC after quenching and tempering at 1220-1250°C. Physical properties stand out with a thermal conductivity of 24.3 W/(m-°C) (at 254°C), but thermoplasticity is low, and overheating needs to be avoided. Coarsening of grains due to overheating needs to be avoided.

S18-0-1 tool steel (DIN standard)

S18-0-1 steel is a Scandinavian/German standard high tungsten high speed steel (SS/DIN) with a strictly limited composition of 17.50-19.00% tungsten, 0.70-0.80% carbon, 1.00-1.40% vanadium. -1.40%. Characteristics emphasise high hardenability and high temperature hardness stability, annealed state hardness ≤ 269 HB, hardness ≥ 63 HRC after quenching in oil at 1270-1285°C and tempering at 550-570°C. Its modulus of elasticity reaches 225 GPa (20°C), but the alloy is more costly and has a narrower machining window (preheating needs to be 820-870°C). -870°C for preheating)

T1 Tool Steel |1.3355 | S18-0-1 Product Types and Options

The table below shows the size range, surface condition and tolerance details for T1,1.3355,S18-0-1 Tool Steel:

Shape	Pocess	Size range	Surface	Tolerance
Flat Bar	Hot Rolled	Thickness: 10-400mm Width: 200-800mm Length: 3000-5800mm	Black; Sandblasted	Thickness :0-+2MM Width:0-+5MM/0-+10MM
	Hot Forged	Thickness: 50-500mm Width: 50-1500mm Length: 3000-5800mm	Black	Thickness:+2-+5MM Width:0-+5MM/0-+10MM
			Turned/Machined/Milled/Bright	Thickness :0-+2MM Width:0-+5MM/0-+10MM
Round Bar	Hot Rolled	Diameter:10-65mm Length:3000-5800mm	Black	0-+2MM
			Turned/Machined	0-+2MM
	Hot Forged	Diameter:70-700mm Length:3000-5800mm	Grinded	0-+5MM/+2-+5MM
			Turned/Machined/Milled/Bright	0-+2MM

T1 Tool Steel |1.3355 | S18-0-1 Customized Options

1. Customized chemical composition: GB, DIN, ASTM, JIS and other standard grades can be produced. Chemical composition can be customized individually.
2. Customized specifications: round steel (diameter), plate (thickness, width) can be customized production.
3. Specialized packaging for long term storage or extreme transportation conditions: includes spraying black paint all around, wrapping plastic film, spraying anti-rust oil, and shipping in wooden crates.
4. Customized production based on samples or technical agreements.
5. 1.3355,T1,S18-0-1 High-Speed Tool Steel Electroslag Remelting (ESR): premium option with higher purity and isotropic properties for critical applications.

T1 Tool Steel |1.3355 | S18-0-1 Chemical composition

Standard/Steel Grade		Chemical Composition(%)
		C	Si	Mn	Cr	V	W
DIN/W-Nr.	S18-0-1/1.3355	0.70~0.78	≤0.45	≤0.40	3.80~4.50	1.00~1.20	17.50~18.50
ASTM	T1	0.65~0.80	0.20~0.40	0.10~0.40	3.75~4.50	0.90~1.30	17.25~18.75
JIS	SKH2	0.73~0.83	≤0.45	≤0.40	3.80~4.50	1.00~1.20	17.20~18.70

T1 Tool Steel |1.3355 | S18-0-1 Heat Treatment Process

1.Annealing

Purpose: to eliminate internal stresses generated during forging or rolling, reduce hardness, improve cutting performance, and prepare for subsequent processing and heat treatment.
Process parameters:
Heating temperature: 800-850 ℃, holding time 2-4 hours, with the furnace cooling to below 500 ℃, and then air-cooled.
Hardness after annealing: ≤ 300 HBS.

2.Quenching

Purpose: to make the tool steel to obtain martensitic organization, improve hardness and wear resistance.
Process parameters:
Heating temperature: 1000-1050 ℃ (commonly used 1020-1040 ℃), holding time according to the size of the workpiece to determine, generally 30-60 minutes.
Cooling: oil cooling or air cooling (for small size or simple shape of the workpiece), large workpieces can be graded quenching (in the 260-300 ℃ salt bath cooling for a period of time and then air-cooled), in order to reduce the quenching stress, to prevent deformation and cracking.

3.Tempering

Purpose: to eliminate quenching stress, adjust the hardness and toughness, stable organization and size.
Process parameters:
low-temperature tempering: 150-250 ℃, insulation 2-3 hours, air-cooled, tempered hardness of 58-62HRC, for molds requiring high hardness and wear resistance.
Medium temperature tempering: 300-500 ℃, insulation 2-3 hours, air-cooled, tempered hardness of 50-58HRC, can improve the toughness, suitable for molds subject to impact load.
High-temperature tempering: 500 ℃ or more, insulation 2-3 hours, air-cooled, tempered hardness 45-50HRC, mainly for the need for higher toughness of the occasion.

4.Precautions

Heating process should control the rate of heating to avoid too rapid a rise in temperature leading to workpiece surface oxidation and decarburization. Protective atmosphere heating can be used or placed in the furnace charcoal and other anti-decarburization agent.
When quenching and cooling, choose the appropriate cooling medium and cooling method according to the shape and size of the workpiece to ensure the quenching effect while reducing the risk of deformation and cracking.
Tempering must be sufficient to ensure the elimination of internal stresses to avoid mold failure due to stress release during use. For large molds or workpieces with complex shapes, multiple tempering can be used.

T1 Tool Steel |1.3355 | S18-0-1 Quality Inspection

1.Surface Condition Inspection

FCS factory has a very strict quality inspection team, we will carefully check the surface condition of each piece of tool steel to ensure that the steel surface is free from cracks, folds, knots, oxidized skin, pitting, scratches and other defects.

2.Chemical Composition Testing

To verify whether the content of alloying elements meets the standard requirements and to safeguard the basis of the mechanical properties of the material. We will let the staff use full-spectrum direct reading spectrometer to analyze multiple elements at the same time. Sampling needs to remove the surface oxidation layer, using a block specimen to stimulate the test.

3.Dimension and Tolerance Inspection

FCS factory will use professional measuring tools to inspect the dimensions and tolerances of the steel to ensure compliance with the customer's contract requirements. Corresponding gauges will be selected according to the dimensional accuracy requirements, including tape measure, high-precision vernier calipers (0.02mm), micrometers (0.001mm), and special inspection gauges. Inspection items cover: diameter, thickness, width, length, hole diameter, chamfering dimensions, etc., to ensure that the tolerances and dimensions meet the contract requirements.

4.Hardness test

Our FCS factory will use professional hardness tester to test the hardness of steel to ensure that it meets the customer's contract requirements.

5.Ultrasonic Testing

Ultrasonic Testing Standard (UT Test Standard) is: Sep 1921-84 Class3 D/d,E/e.
FCS factory uses ultrasonic testing equipment to detect macro defects inside the material (such as cracks, shrinkage holes, inclusions, white spots, etc.), and every piece of round steel and plate will be examined by a second flaw detection test before shipment to ensure that the quality is qualified before shipment.

6.Microstructure Inspection

(1) Metallographic Analysis

FCS factory will use metallographic analysis instrument to detect the microstructure state after heat treatment, including carbide distribution, martensite morphology, residual austenite content, etc.

 (2) Grain size rating

FCS factory will use the comparative method to determine the austenite grain size by comparing the microstructure of the specimen with the standard rating chart, to ensure that it meets the customer's requirements.

T1 Tool Steel |1.3355 | S18-0-1 Technical Specifications

Property	Specification	Test Method
Density	8.7 g/cm³	ASTM B311
Hardness (Annealed)	229 HBS	ASTM E10
Hardness (Hardened)	62–65 HRC	ASTM E18
Tensile Strength	1800–2000 MPa	ASTM E8
Compressive Strength	2800–3100 MPa	ASTM E9
Elastic Modulus	217 GPa	ASTM E111
Thermal Conductivity	21 W/m·K at 20°C	ASTM E1461
Coefficient of Thermal Expansion	9.8 × 10⁻⁶/K (20–400°C)	ASTM E228
Magnetic Permeability	Ferromagnetic	ASTM A342
Machinability	40–45% (relative to AISI 1212)	-
Maximum Service Temperature	600°C	-

T1 Tool Steel |1.3355 | S18-0-1 Product Applications

Key application scenarios

High performance cutting tools

Our T1 tool steel excels in metal cutting applications where tools must maintain a sharp edge at high temperatures and pressures. Cutting tools made from our premium T1 tool steel last 40-60% longer when machining difficult-to-machine materials such as Inconel, titanium alloys and hardened steels. The high tungsten content creates a stable carbide that resists softening, even at cutting edge temperatures of 500-600°C in continuous high-speed machining operations.

Cold work punches and dies

The superior wear resistance of our T1 tool steel makes it ideal for stamping, dropping and forming operations involving abrasive or high-strength materials. Manufacturers report 3-5 times longer tool life when using our precision-ground T1 tool steel to produce complex shapes for electrical laminations and thick structural parts. The combination of high hardness and sufficient toughness prevents progressive wear and catastrophic failure.

Hot Work Applications

Unlike many tool steels that lose their hardness at elevated temperatures, our T1 grade maintains its mechanical properties when subjected to heat for extended periods of time. Moulds and forming tools made from our vacuum heat-treated T1 steels excel in operations such as hot forging, hot extrusion and hot stamping of high-strength steels. The stability of tungsten carbides at high temperatures prevents premature tool failure and dimensional changes during operation.

Precision Measuring and Gauging Tools

The dimensional stability and wear resistance of T1 tool steel make it ideal for precision measuring instruments and gauging tools. Our specially treated T1 material is subjected to multiple stress relieving cycles and deep cooling to ensure minimal dimensional change over time. Quality control laboratories and inspection departments rely on our T1 steel for reference gauges and measuring fixtures where long-term dimensional accuracy is critical.

Wood and paper cutting tools

The excellent edge retention of T1 tool steel makes it particularly valuable when processing highly abrasive materials such as fibre-reinforced wood products, laminates and speciality papers. Planer knives, slitting blades and circular saw blades made from our T1 steel cut these materials with 2-3 times longer service intervals between resharpening, significantly reducing downtime and resharpening costs.

Industry-specific applications

Erospace Manufacturing

Our high purity T1 tool steel provides aerospace manufacturers with broaches, milling cutters and forming tools for machining complex titanium and nickel-based high temperature alloy components. Thermal stability and wear resistance ensure consistent part quality and dimensional accuracy in high-volume production of critical flight components.

Automotive production

Automotive manufacturers and suppliers use our T1 steels for stamping dies, decorative tools and specialised cutting tools in high-volume production environments. The consistency of our material helps maintain tight part tolerances while withstanding millions of production cycles in stamping and forming operations for body components and powertrain parts.

Energy

The oil, gas and power generation industries rely on our T1 tool steel for specialised cutting tools and wear parts used in harsh environments. Applications include drilling components, specialised taps for high-strength pipe connections, and cutting tools in the manufacture of turbine components where heat resistance and edge retention are critical.

Medical Device Manufacturing

The biocompatibility and high-precision capabilities of our T1 steel make it suitable for tooling in medical device production. Cutting instruments, forming dies and precision measuring gauges made from our certified T1 materials ensure consistent quality in the production of surgical instruments and implantable devices.

Defence Industry Applications

Military specifications often require the superior performance characteristics of tungsten tool steels. Our T1 grade materials are used in the production of specialised cutting tools, gauges and components for defence manufacturing, where reliability under extreme conditions and long service life are mandatory.

T1 Tool Steel |1.3355 | S18-0-1 Competitive Advantage Comparison

Characteristic	FCS's T1/1.3355/S18-0-1 Tool Steel	Market Standard Products
Chemical Homogeneity	More consistent heat treatment response and performance	Typical ±0.3–0.5% variation
Inclusion Rating	Higher toughness and surface finish capability	Typical A3 Thin/B4 Heavy
Dimensional Tolerance	Smaller tolerance, reducing machining allowance for faster processing	Large and unstable tolerance
Heat Treatment Package	Excellent microstructure and dimensional stability	Single atmosphere hardening + double tempering
Metallurgical Support	Custom solutions for specific application challenges	Limited or outsourced technical support
Certification Package	Complete traceability and quality documentation	Only basic material certification
Processing Capability	Integrated heat treatment, grinding, and machining; single-source responsibility and quality control	Only material supply or limited processing

T1 Tool Steel |1.3355 | S18-0-1 Customer Success Stories

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T1 Tool Steel |1.3355 | S18-0-1 Pricing Structure Information

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T1 Tool Steel |1.3355 | S18-0-1 Frequently Asked Questions

Q:What is the difference between the names T1, 1.3355 and S18-0-1?
A:These are different standard designations for the same basic steel composition: T1 is the AISI standard (USA), 1.3355 is the DIN/EN standard (Europe) and S18-0-1 is the Swedish standard. All refer to 18% tungsten high-speed tool steels with similar composition ranges.

Q:What is the optimum hardening temperature for T1 tool steel?
A:The recommended austenitising (hardening) temperature is 1230-1280°C (2250-2340°F). The exact temperature should be selected based on the specific application and the desired carbide structure.

Q:How does T1 compare to M2 HSS?
A:T1 has a higher tungsten content (18% vs. 6% for M2) but lower molybdenum and vanadium content. t1 generally provides better hot hardness and wear resistance, while M2 steel provides better toughness and is easier to machine in the annealed condition.

Q: What is the recommended tempering programme for T1 steels?
A: Optimum results require triple tempering at 540-560°C (1000-1040°F) for 2 hours per cycle with complete cooling to room temperature between cycles. This promotes secondary hardening while ensuring dimensional stability.

Q: Can T1 tool steel be machined after heat treatment?
A: Limited machining in the hardened condition can be performed using CBN or ceramic tools. However, grinding, EDM and wire EDM are the preferred methods for machining hardened T1 steels. Complex machining should be done in the annealed condition.