Introduction to Tool Steel CNC Machining
Tool steel is the backbone of industrial manufacturing, engineered for extreme hardness, exceptional wear resistance, and unwavering durability under relentless pressure. Unlike standard steels, tool steels are specifically formulated to cut, shape, and form other materials, making them indispensable for molds, dies, and high-performance tooling. At Clarwe, we specialize in precision machining of a comprehensive range of tool steel grades, combining specialized expertise with rigorous quality control to deliver components that withstand the most demanding applications.
Key Advantages of Tool Steel:
Tool Steel vs. Other Materials
While materials like aluminum, stainless steel, and plastics serve many purposes, tool steel stands alone when performance under extreme conditions is non-negotiable. Compared to stainless steel, tool steel offers superior wear resistance and can achieve much higher hardness levels. Unlike aluminum, it maintains its structural integrity under heavy load and high-temperature conditions. And while more challenging to machine than either material, tool steel provides unmatched durability for tooling and industrial applications where failure is not an option.
| Material | Hardness | Wear Resistance | Machinability | Cost | Best For |
|---|---|---|---|---|---|
| Tool Steel | Very High (50-65 HRC) | Exceptional | Fair to Difficult | $$$$ | Molds, dies, punches, industrial tooling |
| Stainless Steel | Medium to High (35-55 HRC) | Good | Good | $$$ | Medical devices, food processing, marine |
| Aluminum | Low (40-80 HB) | Poor | Excellent | $$ | Aerospace, automotive, consumer products |
| Plastics | Very Low (30-120 Rockwell R) | Poor | Excellent | $ | Enclosures, prototypes, low-stress parts |
Tool Steel Alloys : Properties and Applications
At Clarwe, we know that selecting the right tool steel is what separates a good part from a great one. Each grade is engineered for a specific purpose, balancing hardness, toughness, and wear resistance. Our network of manufacturing partners allows us to source and precision-machine a comprehensive range of tool steels, ensuring your molds, dies, and tooling components perform flawlessly under pressure.
Common Tool Steel Alloys & Their Uses
A2 Tool Steel
The all-rounder. Excellent stability during heat treatment with good wear resistance, ideal for blanking dies, forming dies, and gauges.
D2 Tool Steel
The wear-resistant workhorse. High carbon and chromium content provides superior resistance to abrasion, perfect for long-run dies, punches, and industrial wear parts.
O1 Tool Steel
The oil-hardening classic. Offers good machinability in its annealed state and can hold a sharp edge, making it a go-to for jigs, fixtures, and master tools.
H13 Tool Steel
The hot work champion. Formulated to retain strength and resist thermal fatigue at high temperatures, it's the standard for die casting molds, extrusion dies, and forging applications.
S7 Tool Steel
The shock absorber. Exceptional impact resistance makes it the premier choice for chisels, punches, shear blades, and other tools subject to heavy pounding.
Technical Specifications of Popular Tool Steel Alloys
| Tool Steel Alloy Type | Hardness (HRC) | Primary Properties | Machinability (Annealed) | Best Applications |
|---|---|---|---|---|
| A2 (Air-Hardening) | 57-62 | Good wear resistance, excellent stability | Good | Dies, gauges, complex tools |
| D2 (High-Carbon, High-Chromium) | 58-64 | Superior wear resistance, moderate toughness | Fair | Long-run dies, punches, wear plates |
| O1 (Oil-Hardening) | 58-64 | Good machinability, can hold sharp edges | Excellent | Jigs, fixtures, cutting tools |
| H13 (Hot-Work) | 38-52 | Excellent thermal fatigue resistance | Good | Die casting molds, extrusion dies |
| S7 (Shock-Resisting) | 54-60 | High impact strength, good wear resistance | Good | Punch and die sets, shear blades |
Choosing the Right Tool Steel for Your Application
The best tool steel for your project depends on the demands it will face. Is wear resistance over thousands of cycles the top priority? D2 is a strong contender. Will the part experience extreme impact? S7 is built for the job. Operating in a high-temperature environment? H13 is the industry standard. If you need a well-balanced alloy that machines well and resists distortion, A2 is an excellent choice.
Our engineers are experts in material selection. During your free DFM analysis, we'll recommend the most effective and cost-efficient tool steel to ensure your component's longevity and performance.
CNC Machining Capabilities for Tool Steel Components
At Clarwe, we specialize in taming the toughest materials. Our network of manufacturing partners is equipped with advanced CNC technology specifically calibrated to handle the unique challenges of machining tool steel. We deliver precision-cut components that meet the extreme demands of tooling, molding, and high-wear applications, combining raw strength with impeccable accuracy.
CNC Milling Services
Tool steel requires power, rigidity, and expertise. Our multi-axis CNC milling centers are up to the task, capable of handling pre-hardened steels and achieving complex geometries with the tight tolerances your tools demand. We employ specialized toolpaths and cutting strategies to manage hardness and prevent work hardening.
- ⇒ Hard Milling: Precision machining of hardened steels up to 64 HRC, reducing or eliminating the need for secondary grinding.
- ⇒ 5-Axis Contouring: Complex, uninterrupted machining of mold cores, cavities, and complex die components in a single setup.
- ⇒ High-Pressure Coolant Systems: Efficient heat and chip management to extend tool life and protect the material's integrity.
- ⇒ Rigid Tapping & Threading: Creating clean, precise threads in tough material without compromising strength.
CNC EDM Services
For the most complex details and sharpest internal corners in hardened tool steel, our Electrical Discharge Machining (EDM) is indispensable. This process uses electrical sparks to erode material with pinpoint accuracy, regardless of hardness.
- ⇒ Wire EDM: For precision punches, stripper plates, and complex die components with tight tolerances and no burrs.
- ⇒ Sinker EDM: Ideal for creating complex mold textures, detailed logos, and sharp angles that are impossible with milling.
- ⇒ Small Hole EDM Drilling: Starting holes for Wire EDM or creating precise coolant channels in hardened materials.
Technical Specifications at a Glance
| Process | Tolerance Capability | Standard Lead Time | Max Part Size | Best For |
|---|---|---|---|---|
| CNC Milling | ±0.01mm | 5-7 days | 1000mm x 600mm x 500mm | Mold bases, complex cores, die sets |
| CNC Turning | ±0.015mm | 4-6 days | Ø400mm x 1000mm | Pins, bushings, shafts, rollers |
| CNC EDM | ±0.005mm | 7-10 days | 600mm x 400mm x 300mm | Complex details in hardened steel, sharp corners |
Whether you need a simple turned pin or a complex multi-cavity mold, we have the specialized equipment and machining expertise to transform your toughest tool steel designs into durable, high-performance reality.
See Our Full CNC Capabilities | Request a Free Consultation | Explore Available Tool Steel Alloys
Surface Finishing Options for Tool Steel Parts
The right finish doesn't just protect your tool steel components—it unlocks their full potential. We offer a comprehensive suite of post-processing services designed to enhance hardness, improve wear resistance, prevent corrosion, and ensure your parts perform flawlessly in the most demanding industrial environments.
Heat Treatment Services
Precisely control the material properties of your tool steel with our specialized heat treating processes. This is where raw machined parts transform into durable, high-performance tools.
• Hardening & Tempering: Achieve the perfect balance of extreme hardness and necessary toughness for your specific application.
• Annealing: Soften material for easier secondary machining or to relieve internal stresses from heavy cutting operations.
• Stress Relieving: Minimize distortion and stabilize the geometry of precision components before final finishing.
• Case Hardening: Create a hard, wear-resistant outer surface while maintaining a tougher, shock-absorbing core.
Plating & Surface Coating
Add an extra layer of protection or modify the surface properties of your tools with our advanced coating technologies.
• Nickel Plating: Provides excellent corrosion resistance and can improve surface lubricity.
• Chrome Plating (Hard Chrome): Offers extreme surface hardness, outstanding wear resistance, and a low coefficient of friction.
• Electroless Nickel Plating: Delivers a uniform, hard coating even on complex geometries with excellent corrosion protection.
• Titanium Nitride (TiN) Coating: A super-hard, gold-colored PVD coating that dramatically increases surface hardness and reduces friction.
Mechanical & Abrasive Finishes
Achieve the precise surface texture, dimensional accuracy, and appearance required for your tooling applications.
• Precision Grinding: Achieve ultra-tight tolerances and superior surface finishes on flat, cylindrical, or surface grounds.
• Polishing & Lapping: Create mirror-like finishes on mold surfaces to improve part release and final product appearance.
• Bead Blasting: Produce a uniform matte finish that hides tool marks and provides a consistent, non-reflective surface.
• Hand Stoning: A skilled manual process to create perfectly flat surfaces, sharpen edges, and prepare tools for final use.
Specialized Treatments
Advanced processes to enhance performance and longevity for specific challenging applications.
• Nitriding: A thermochemical process that diffuses nitrogen into the surface, creating an extremely hard case with superior fatigue strength.
• Passivation: A chemical process that removes free iron from the surface, enhancing the natural corrosion resistance of stainless tool steels.
• Laser Engraving: Permanently mark parts with logos, serial numbers, or identification codes for traceability.
Tool Steel Surface Finishing Comparison
| Finish Type | Hardness (HRC) | Wear Resistance | Corrosion Resistance | Best Applications |
|---|---|---|---|---|
| Hard Chrome Plating | 68-72 | Exceptional | Excellent | Hydraulic cylinders, gauges, wear surfaces |
| Titanium Nitride (TiN) | 80+ | Superior | Good | Cutting tools, injection molds, punches |
| Nitriding | 60-70 | Excellent | Very Good | Gears, crankshafts, die-casting dies |
| Precision Grinding | N/A (Improves Form) | N/A (Improves Form) | N/A | Achieving final tolerances, flatness, parallelism |
| Bead Blasting | N/A | N/A | Fair (Removes Stains) | Aesthetic uniformity, preparing surfaces for coating |
From the furnace to the final polish, our finishing experts will recommend and execute the optimal treatment to ensure your tool steel parts meet the highest standards of performance and durability. Every process is backed by our in-house QAQC to guarantee consistent, certified results.
Tool Steel CNC Machining Applications by Industry
Tool steel is the backbone of manufacturing, forming the durable, high-performance components that production lines and heavy machinery rely on. At Clarwe, we machine precision tool steel parts that meet the extreme demands of industries where failure is not an option, from the high-impact forces of metal stamping to the relentless heat of die casting.
Mold & Die Manufacturing
The heart of mass production. We machine the precise molds and dies that shape everything from plastic bottles to car doors, ensuring they withstand millions of cycles with minimal wear.
• Injection mold cores, cavities, and inserts
• Die casting molds and extrusion dies for aluminum and zinc
• Stamping dies, punch pads, and progressive die components
• Blow molds for plastic containers and packaging
• Forging dies and tooling for metal forming
Automotive & Aerospace Manufacturing
Where extreme precision meets relentless demand. Our tool steel components are integral to the specialized machinery and assembly systems that build vehicles and aircraft.
• Jigs and fixtures for precision welding and assembly
• Custom cutting tools, form tools, and tool holders
• Gages, check fixtures, and quality control equipment
• Wear plates, guide pins, and bushings for production machinery
• Robotic end-effectors and automation components
Consumer Goods & Packaging
Behind every mass-produced product is a tool steel component. We help create the durable tooling that enables high-volume production of consumer items with consistent quality.
• Cutting dies for packaging and label materials
• Mold inserts for plastic appliance components
• Embossing and engraving rolls for textured surfaces
• Slitter blades and rotary cutters for continuous materials
• Custom fastening and assembly tooling
Heavy Industry & Machinery
Keeping industry moving with components built to last. Our machined tool steel parts withstand the abrasive, high-impact environments of mining, construction, and heavy equipment.
• Wear parts for conveyor systems and material handling
• Cutting edges and teeth for earth-moving equipment
• Valve components and seals for high-pressure systems
• Shafts, gears, and sprockets for power transmission
• Custom machine components and replacement parts
Energy & Oil & Gas
Operating in the world's most demanding environments. We produce tool steel components that maintain integrity under extreme pressures, temperatures, and corrosive conditions.
• Downhole tool components for drilling operations
• Valve trims and choke components for flow control
• Inspection and measurement tools for pipeline maintenance
• Pump components and impellers for abrasive fluids
• Specialized tooling for turbine maintenance and repair
Industry Applications at a Glance
| Industry | Common Alloys | Key Requirements | Typical Components |
|---|---|---|---|
| Mold & Die | H13, P20, S7 | Heat resistance, wear resistance, polishability | Mold cores, stamping dies, inserts |
| Automotive | D2, A2, O1 | High wear resistance, durability, precision | Jigs, fixtures, wear plates, gages |
| Consumer Goods | D2, O1, A2 | Sharpness, fine detail, long service life | Cutting dies, embossing rolls, slitter blades |
| Heavy Industry | D2, S7, H13 | Impact resistance, abrasion resistance | Wear parts, cutting edges, machine components |
| Energy | H13, D2, S7 | Corrosion resistance, high pressure/temperature | Downhole tools, valve components, pump parts |
No matter how demanding your application, our engineering team understands the brutal environments your tool steel parts must endure. We deliver components hardened, finished, and certified to not just meet specifications, but to dramatically extend your tool life and reduce production downtime.
Quality Assurance and Certifications for Tool Steel Components
At Clarwe, we understand that tool steel components are the workhorses of industry—they must perform flawlessly under extreme pressure. That's why our quality assurance quality process is engineered to verify not just dimensions, but durability, hardness, and long-term performance. From material certification to final inspection, we deliver tool steel parts built to withstand the test of time and torque.
| Certifications & Compliance |
Our quality management system is built on internationally recognized standards, ensuring excellence across all industries we serve: ISO 9001:2015 Certified: Our foundation for consistent quality management IATF 16949:2016 Certified: Automotive quality management system compliance ISO 13485:2016 Certified: Medical device quality management standards ISO 14001:2015 Certified: Environmental management system certification Supplier Quality Audits: Regular audits of our manufacturing network partners |
| Quality Control Processes |
Our multi-layered inspection protocol ensures every tool steel component meets rigorous standards: Material Verification: Authentication of steel grade and heat lot certification First Article Inspection (FAIR): Comprehensive validation of initial production parts In-Process Inspection: Real-time monitoring of critical dimensions during machining Hardness Verification: Rockwell testing to ensure proper heat treatment specifications Final Comprehensive Inspection: Full dimensional and visual verification before shipment |
| Advanced Inspection Equipment |
We deploy state-of-the-art metrology equipment specifically suited for verifying tool steel components: Coordinate Measuring Machines (CMM): ±0.005mm accuracy for complex mold geometries Rockwell Hardness Testers: Material hardness verification to ensure proper heat treatment Optical Comparators: 2D profile measurement for punch and die components Surface Roughness Testers: Quantitative surface finish validation for mold surfaces Digital Height Gauges & Micrometers: Precision measurement of critical dimensions |
| Quality Documentation |
We provide complete traceability and verification with every order: Certificate of Conformity: Material and specification compliance certification Material Test Reports: Full traceability to mill origin and heat treatment records First Article Inspection Reports: Detailed initial part validation documentation Hardness Test Reports: Verification of achieved hardness values Surface Finish Reports: Quantitative measurement of surface roughness |
| Industry-Specific Compliance |
Our quality systems meet the strict requirements of regulated industries: Automotive: PPAP levels 1-5, statistical process capability reporting Medical: ISO 10993 biocompatibility support, sterilization validation documentation Aerospace: AS9102 FAIR, flight-critical documentation support Industrial: Process validation, capability studies, and wear testing documentation |
Quality Capabilities Overview
| Inspection Method | Accuracy Capability | Best For | Industry Applications |
|---|---|---|---|
| CMM Inspection | ±0.005mm | Complex 3D geometries, free-form surfaces | Mold & die, aerospace |
| Hardness Testing | ±1.0 HRC | Material property verification | Automotive, industrial tools |
| Surface Roughness | ±0.001μm | Surface finish validation | Injection molds, precision components |
| Optical Measurement | ±0.002mm | 2D profiles, contour verification | Punch & die, stamping tools |
| Visual Inspection | N/A | Cosmetic defects, tool marks | Consumer products, visible components |
From the moment raw material enters our network to the final inspection of your finished tool steel components, our quality assurance team delivers more than just parts—we deliver reliability. Every component comes with the documentation and certification you need to build with confidence, ensuring your tools perform exactly as engineered, cycle after cycle.
Get a Project Review | Contact Our Engineering Team | Request a Callback
Design Guidelines for Tool Steel CNC Machining
Designing with tool steel requires a different mindset than conventional materials. These alloys are chosen for extreme applications, and your design must balance ultimate performance with smart manufacturability. Follow these expert guidelines to create tool steel components that achieve maximum durability while optimizing machining efficiency and cost. Our engineers provide free Design for Manufacturability (DFM) analysis to ensure your designs are production-ready.
Key Design Considerations
- Wall Thickness: Maintain minimum 2.0mm wall thickness for stability during and after heat treatment
- Internal Corners: Use generous radii (recommended: R2mm minimum) to prevent stress concentration and tool wear
- Hole Depth: Limit through holes to 3x diameter, blind holes to 2x diameter in hardened materials
- Threading: Specify threads before heat treatment when possible; avoid fine threads in hardened steel
- Sharp Edges: Add small chamfers (0.2mm min) to prevent chipping during handling and heat treatment
- Tolerances: Specify critical dimensions only; allow more generous tolerances on non-functional features
Standard Machining Tolerances
- Standard Machining (Annealed): ±0.05mm (±0.002")
- Precision Machining (Annealed): ±0.025mm (±0.001")
- Hard Machining (Hardened >45 HRC): ±0.075mm (±0.003")
- Grinding/EDM (Hardened): ±0.005mm (±0.0002")
- Surface Finish: Standard Ra 1.6μm, fine machining Ra 0.4μm achievable
Recommended Design Parameters for Tool Steel
| Feature Type | Recommended Value | Minimum Value | Design Tip |
|---|---|---|---|
| Wall Thickness | 3.0mm | 2.0mm | Thicker walls prevent distortion during heat treat |
| Internal Corner Radius | R2mm | R0.5mm | Larger radii extend tool life and reduce stress |
| Hole Diameter | Standard drill sizes | 1.0mm | Depth ≤ 3x diameter, especially in hardened state |
| Thread Size | M6 and larger | M4 | Specify coarse threads for better strength in hardened parts |
| Chamfer Size | 0.5mm | 0.2mm | Protects edges from chipping during handling |
| Minimum Feature Size | 2.0mm | 1.0mm | Consider material toughness for small, delicate features |
Design for Manufacturing Tips
• Design Symmetrically: Balanced designs warp less during heat treatment
• Avoid Thin Walls Next to Mass: Prevent cracking by maintaining consistent wall thickness
• Specify Heat Treatment State: Indicate if machining will be done annealed or hardened
• Consider EDM Alternatives: Design features that can be wire or sinker EDM'd if hard machining is costly
• Add Tool Access: Ensure end mills can reach all features without collision
• Design for Grinding: Include grinding allowances if secondary operations are needed
• Mark Critical Surfaces: Identify areas requiring specific hardness or finish
Cost-Saving Design Strategies
• Machine Annealed When Possible: Significantly faster machining speeds in soft state
• Minimize Hard Machining: Design features that can be completed before final hardening
• Use Standard Features: Avoid custom form tools and special cutters
• Group Tolerances: Keep tight tolerances only on functional surfaces
• Design for Standard Stock: Size parts to common tool steel blank dimensions
• Avoid Unnecessary Finishing: Specify surface finishes only where critical for function
• Combine Operations: Design features that can be machined in single setups
Design for Durability Considerations
• Radius All Stress Points: Eliminate sharp corners where cracks can originate
• Specify Proper Hardness: Match hardness to application requirements (wear vs. impact)
• Consider Surface Treatments: Design for nitride, chrome, or other coatings where appropriate
• Design for Repair: Include features that allow for refurbishment and sharpening
• Thermal Management: Incorporate cooling channels or thermal relief features for hot work tools
Even the most complex tool steel designs can be optimized for manufacturing. Upload your CAD files for a free DFM analysis and online quote to see how our expertise with tool steels can bring your most demanding components to life with unmatched precision and durability.
Why Choose Clarwe for Tool Steel CNC Machining?
When your project demands uncompromising strength and precision, Clarwe delivers tool steel components that perform under pressure. We combine specialized material expertise with rigorous quality control to produce parts that generic manufacturing platforms simply can't match. Here's why engineers trust us with their most critical tooling applications:
Specialized Tool Steel Expertise
➤ Comprehensive Alloy Selection: From wear-resistant D2 to shock-absorbing S7 and hot-work H13
➤ Material Scientists On Staff: Get expert grade recommendations for your specific application environment
➤ Heat Treatment Integration: In-house or partnered hardening, tempering, and stress relieving
➤ Free DFM Analysis: Detailed design feedback to optimize your tool steel part for performance and manufacturability
Precision Built to Endure
➤ Hardness Verification: In-house Rockwell testing to ensure specified hardness values (HRC)
➤ First-Article Inspection: Comprehensive validation for mission-critical tooling components
➤ ISO 9001 & IATF 16949 Certified: Meeting automotive and industrial quality standards
➤ Full Material Traceability: Mill test reports and heat treatment documentation with every order
The Clarwe Advantage: Manufacturing Partnership
➤ Unlike automated platforms, every Clarwe project receives specialized engineering oversight from quote to delivery
➤ Our manufacturing experts understand tool steel's unique challenges and become an extension of your team, providing proactive solutions for even the most complex tooling applications
Clarwe vs The Competition
| Capability | Clarwe | Typical Machine Shops | Online Platforms |
|---|---|---|---|
| Material Expertise | Tool Steel Specialists | General Materials | Limited Selection |
| Heat Treatment | Integrated Process Management | Often Outsourced | Partner-Dependent |
| Hardness Verification | In-House Rockwell Testing | Variable | Usually Not Offered |
| Quality Documentation | Full Material Traceability | Additional Cost | Limited |
| Engineering Support | Dedicated Tooling Expert | Limited Availability | Automated Only |
| Surface Finishes | Specialized Tool Steels Finishes | Standard Options | Limited Selection |
Seamless Process, Certified Results
➤ Online Quoting: Upload your CAD file for immediate pricing➤ Real-Time Project Tracking: Monitor your order with updates at every production stage
➤ Comprehensive Certification: Receive full material traceability and heat treatment documentation
➤ Dedicated Support: Single point of contact throughout your project
Proven Reliability for Demanding Applications
➤ 520+ Manufacturing Partners: Global network with specialized tool steel capabilities➤ Risk-Free Sourcing: We manage quality across our entire partner network
➤ Production Flexibility: From single prototypes to full production runs
➤ No Hidden Costs: Competitive pricing with complete transparency
Join engineers who trust Clarwe for their most demanding tool steel components. Experience the difference that specialized manufacturing expertise makes—upload your CAD files today for a free, no-obligation quote and detailed DFM analysis.
Frequently Asked Questions About Tool Steel CNC Machining
Tool Steel vs. Other Materials for Tooling Applications
| Consideration | Tool Steel | Stainless Steel | Aluminum | Carbon Steel |
|---|---|---|---|---|
| Maximum Hardness | 64+ HRC | 55 HRC | 40 HRC | 62 HRC |
| Wear Resistance | Excellent | Good | Poor | Very Good |
| Impact Resistance | Good to Excellent | Fair | Poor | Good |
| Heat Resistance | Excellent | Good | Poor | Fair |
| Machinability | Fair to Difficult | Fair | Excellent | Good |
| Cost | $$$$ | $$$ | $$ | $$ |