Learn what X46Cr13 stainless steel is, when it is used for CNC machining, how it compares with maraging steel, and how to manage hardness, surface finish, heat treatment, and inspection risks for custom precision parts.
What Is X46Cr13 Stainless Steel?
X46Cr13 is a European martensitic stainless steel commonly identified by material number 1.4034. It belongs to the 13% chromium stainless steel family and is often compared with high-carbon 420-type stainless grades. The name itself is useful for engineers: “X” indicates a high-alloy steel, “46” points to about 0.46% carbon, and “Cr13” indicates roughly 13% chromium. This combination gives the material a different personality from common austenitic stainless steels such as 304 or 316. Instead of being selected primarily for maximum corrosion resistance, X46Cr13 is usually selected when a machined part needs hardness, wear resistance, polishability, and moderate corrosion resistance in one material.
Material Identity
In CNC machining projects, X46Cr13 is best understood as a hardenable stainless steel. It is usually supplied in a soft annealed condition for easier machining and can then be hardened and tempered to obtain higher strength and wear resistance. This is why it appears in precision components where a sharp edge, sliding surface, polished surface, or wear-resistant functional face is important. However, the same carbon content that supports hardening also makes it less forgiving than low-carbon stainless steel during machining and heat treatment.
Common Names and Equivalents
The exact equivalent depends on the standard, product form, and supplier specification, so buyers should always confirm the material certificate rather than relying only on a commercial name. In practical sourcing, the following terms may appear around the same material family:
| Name or Standard | Typical Reference | Meaning for CNC Projects |
| EN short name | X46Cr13 | European designation used on drawings and material requests |
| Material number | 1.4034 | Common European material number for traceability |
| Family comparison | 420C-type martensitic stainless | Useful for international sourcing, but should not replace certificate verification |
| Delivery condition | Soft annealed, quenched and tempered | Machinability and final hardness depend strongly on condition |
Core Material Character
The most important point is that X46Cr13 is not “just another stainless steel.” It is magnetic, heat-treatable, polishable, and more wear resistant than many general-purpose stainless grades. At the same time, it has lower corrosion resistance than many austenitic stainless steels and needs careful process planning if the final part must meet both dimensional and surface requirements.
Is X46Cr13 Commonly Used for CNC Machining?
Yes, X46Cr13 can be used for CNC machining, but it is not normally treated as an easy free-machining stainless steel. It is more often chosen for functional stainless parts where the final performance justifies stricter control of tooling, heat treatment, and finishing. The material is suitable for CNC turning, CNC milling, drilling, reaming, threading, grinding, and polishing when the supplier understands its condition and the required final hardness. For buyers searching for X46Cr13 CNC machining services, the key question is not whether the alloy can be machined, but whether the supplier can control distortion, burrs, tool wear, surface finish, and post-machining heat treatment.
Why CNC Machining Is Used
CNC machining is preferred when the part has precise sealing faces, stepped shafts, holes, threads, slots, grooves, or polished functional surfaces. Compared with simple cutting or forming operations, CNC machining gives better control over geometry and repeatability. For X46Cr13, this matters because many parts made from this alloy are not purely decorative; they often need stable fit, smooth contact, controlled edge quality, or reliable movement against another component.
Typical CNC Operations
The following operations are common when X46Cr13 is made into custom precision parts. The final route depends on whether the part is machined before hardening, after hardening, or with finish machining after heat treatment.
| CNC Operation | Typical Features | Main Concern |
| CNC-Drehen | Shafts, pins, sleeves, cylindrical seats | Heat buildup, tool wear, surface finish |
| CNC-Fräsen | Flats, pockets, mounting faces, slots | Work hardening risk and edge chipping |
| Drilling and reaming | Precision holes, assembly holes, flow holes | Burrs, hole straightness, tool breakage |
| Gewindeschneiden | Internal and external threads | Galling, burrs, pitch accuracy |
| Grinding or polishing | Sealing surfaces, sliding faces, appearance surfaces | Dimensional change and surface integrity |
When It Is a Good CNC Choice
X46Cr13 becomes a good CNC choice when the design requires stainless behavior plus hardness after heat treatment. If the part only needs general corrosion resistance and easy machining, another stainless grade may be more economical. If the part needs very high strength with excellent dimensional stability after aging, maraging steel may be more suitable. For X46Cr13, the strongest use case is a part that must resist wear, hold a clean edge or polished surface, and still offer reasonable corrosion resistance in a non-extreme environment.
What CNC Machined Parts Use X46Cr13?
X46Cr13 is commonly associated with precision components that need hardness, polishability, and moderate corrosion resistance. In CNC machining, it is especially relevant for parts that experience sliding contact, repeated movement, cutting or scraping action, sealing contact, or frequent cleaning. Because it can be hardened, X46Cr13 is used where softer stainless steels may wear too quickly. However, it should not be presented as a universal stainless solution. Its value comes from matching the heat-treated properties to the working condition of the part.
Industrial and Mechanical Components
For industrial CNC parts, X46Cr13 can be selected for pump components, valve-related parts, shafts, bushings, wear plates, seats, guides, and small mechanical elements. These parts often require more than corrosion resistance. A pump component may need a polished surface to reduce friction. A valve-related part may need a stable sealing face. A shaft or guide may need hardness to resist wear while still being machinable during production.
Application Selection Table
The table below summarizes typical CNC part categories where X46Cr13 may be considered. Final suitability still depends on environment, hardness target, heat treatment, surface finish, and inspection requirements.
| Teilkategorie | Why X46Cr13 May Be Selected | Important Design Check |
| Pump components | Wear resistance, polishability, stainless behavior | Confirm liquid environment and surface finish |
| Valve-related components | Hardenable surface and dimensional control | Confirm sealing area tolerance and heat treatment route |
| Shafts and pins | Strength, wear resistance, magnetic martensitic structure | Confirm straightness after heat treatment |
| Bushings and guides | Sliding wear resistance and polishability | Confirm mating material and lubrication |
| Precision plates and seats | Hard surface and stable contact area | Confirm flatness after hardening and finishing |
Where Buyers Should Be Careful
A common concern in customer discussions is whether X46Cr13 is corrosion resistant enough for the intended environment. The answer depends on exposure. It can perform well in many indoor, mildly corrosive, or frequently cleaned environments, especially when surface finish is controlled. It is not the same as 316 stainless steel in chloride-rich or highly corrosive service. If the application involves aggressive chemicals, long outdoor exposure, or salt-containing environments, the material choice should be reviewed before quoting.
Why Do Users Choose Maraging Steel for CNC Machined Parts?
Maraging steel is a different material concept from X46Cr13. Users usually choose maraging steel when they need ultra-high strength, high toughness, good machinability before aging, and predictable dimensional change during heat treatment. The word “maraging” comes from martensite plus aging, because the alloy gains strength mainly through aging treatment rather than high carbon. This makes it attractive for precision CNC parts that must be machined accurately in a softer condition and then strengthened after machining with less distortion than many conventional hardening steels.
Main Reasons for Choosing Maraging Steel
In custom CNC machining, maraging steel is not usually the cheapest option. It is chosen when performance, stability, or manufacturing reliability matters more than raw material cost. Buyers often consider it for high-strength tooling, mold inserts, precision mechanical components, aerospace-related structures, high-load shafts, dies, fixtures, and prototype parts that must survive demanding testing.
Decision Drivers
The main reasons are technical rather than cosmetic. Maraging steel gives designers a way to combine high strength with good toughness and machining predictability. It is also useful when tight tolerances must be maintained after heat treatment.
| Grund | Warum es bei der CNC‑Bearbeitung wichtig ist | Typical Buyer Concern |
| High strength after aging | Supports demanding load-bearing parts | Will the part deform after heat treatment? |
| Good machinability before aging | Allows complex shapes to be machined before final hardening | Can the supplier hold tight tolerances economically? |
| Low-carbon alloy design | Reduces cracking risk compared with many high-carbon steels | Is the part reliable under stress? |
| Dimensionsstabilität | Helps finish-machined features remain predictable | How much stock should be left before aging? |
| Toughness | Improves resistance to sudden failure in high-load use | Can the part survive testing or repeated loading? |
When Maraging Steel Is Not the Best Choice
Maraging steel should not be selected only because it sounds premium. It is generally more expensive than standard stainless and alloy steels, and it may need surface protection if corrosion resistance is critical. If the design mainly needs moderate corrosion resistance, polishability, and wear resistance, X46Cr13 may be more direct. If the design mainly needs ultra-high strength and dimensional stability after aging, maraging steel is easier to justify.
X46Cr13 Chemical Composition
The composition of X46Cr13 explains its CNC machining behavior. Carbon gives the steel hardenability and wear resistance, while chromium provides stainless behavior and contributes to carbide formation. The alloy is simpler than maraging steel, but the carbon-chromium balance has a strong effect on hardness, polishability, tool wear, and corrosion resistance. In sourcing and CNC quotation, the exact composition range should be confirmed by the material standard and mill certificate, especially when the part requires heat treatment or polishing.
Typischer Zusammensetzungs‑Bereich
X46Cr13 is usually specified around 0.43-0.50% carbon and 12.5-14.5% chromium, with silicon and manganese controlled at low levels. Phosphorus and sulfur are limited because they affect toughness, polishability, and machining behavior. Some standards allow controlled sulfur ranges for machinability, but polishing requirements may call for lower sulfur content.
Composition Table
The values below are practical reference ranges for engineering discussion. They should not replace the material certificate for final production.
| Element | Typischer Bereich oder Grenzwert | Effect on CNC Machined Parts |
| C | 0.43-0.50% | Improves hardenability and wear resistance; increases tool wear risk after hardening |
| Cr | 12.5-14.5% | Provides stainless behavior and supports hardness; improves polishability when controlled |
| Si | Max. 1.0% | Supports deoxidation; excessive levels may affect processing |
| Mn | Max. 1.0% | Helps steelmaking control; affects hardenability slightly |
| P | Max. 0.04% | Kept low to protect toughness and quality |
| S | Usually low or controlled | Can improve machinability but may reduce polishability if too high |
How Composition Affects Machining
The carbon and chromium content mean the material can form hard carbides, especially after heat treatment. In the annealed condition, CNC machining is more manageable, but it still requires sharp tools, stable clamping, and good coolant delivery. In hardened condition, machining becomes much more difficult and may require grinding, hard milling, or specialized finishing operations. This is why process planning should decide early whether critical dimensions are machined before or after heat treatment.
X46Cr13 Physical and Mechanical Properties
The useful properties of X46Cr13 depend strongly on heat treatment condition. In the soft annealed condition, it is easier to cut but has lower final strength. In the quenched and tempered condition, it gains higher tensile strength and hardness, but machining becomes more difficult. For CNC buyers, this means the drawing should not only say “X46Cr13”; it should also define the required condition, hardness range, surface finish, and critical dimensions after heat treatment.
Physikalische Eigenschaften
X46Cr13 has a density close to 7.7 g/cm³ and thermal conductivity around the mid-20 W/m·K range. Its thermal expansion is moderate for steel. These values matter during CNC machining because heat management affects size control, surface finish, and tool life. A part with thin walls, long shafts, or tight flatness requirements can move during machining or after heat treatment if stress is not controlled.
Property Reference Table
The following table gives a practical overview for design and machining discussions. Exact values vary with supplier, product form, heat treatment, and testing standard.
| Eigenschaft | Typical Reference | CNC Machining Meaning |
| Dichte | About 7.7 g/cm³ | Similar weight class to other steels |
| Wärmeleitfähigkeit | About 24-26 W/m·K | Heat should be controlled with coolant and tool strategy |
| Thermal expansion | About 10.5-11.6 x 10^-6/K from 20-400°C | Heat treatment and machining temperature can affect dimensions |
| Annealed hardness | Up to about 245 HB | Preferred condition for rough machining |
| Quenched and tempered tensile strength | Often around 850-1000 MPa depending on condition | Supports stronger wear-resistant parts |
| Dehnung | Often around 10-12% in referenced conditions | Lower ductility than many austenitic stainless steels |
Mechanical Property Interpretation
The most important mechanical property is not a single number; it is the combination of hardness, strength, toughness, and surface condition after heat treatment. If a part needs high wear resistance, the final hardness target should be specified. If it needs tight tolerance, the manufacturer may rough machine, heat treat, then finish grind or finish machine. If it needs a polished surface, sulfur level, inclusion quality, and final finishing route become important.
What Do Customers Usually Discuss About X46Cr13?
The most common questions around X46Cr13 are practical. Buyers ask whether it is stainless enough, whether it can be hardened, whether it is difficult to machine, and whether it is a good alternative to more familiar stainless grades. These questions matter because the material sits between several categories: it is stainless, but not highly corrosion resistant like 316; it is hardenable, but not as dimensionally stable after aging as maraging steel; it is machinable, but not as easy as free-machining stainless steel.
Corrosion Resistance and Environment
A frequent concern is whether X46Cr13 will rust. The careful answer is that it has moderate corrosion resistance when properly heat treated, finished, and cleaned, but it is not intended for every corrosive environment. Surface roughness, heat tint, contamination, and trapped moisture can all reduce corrosion performance. For CNC parts, a smoother surface and proper cleaning can improve performance in mild environments, while harsh environments may require another material or surface protection.
Questions That Should Be Answered Before Production
Before choosing X46Cr13 for a precision machined part, the engineering team should confirm the service condition rather than relying on the word stainless.
- Will the part contact water, cleaning chemicals, salt-containing fluids, or abrasive media?
- Is the part expected to be polished, passivated, hardened, or ground?
- Which surfaces are functional, cosmetic, or sealing surfaces?
- Are dimensions required before or after heat treatment?
- Is the required hardness compatible with the tolerance and surface finish?
Hardness and Surface Finish
Another common discussion is whether the part should be machined soft and hardened later, or machined after hardening. For most precision components, rough machining before heat treatment and finish machining afterward gives better control. If the part is fully machined before hardening, there may be distortion or size change. If the part is machined only after hardening, tool wear and cost increase. The best route depends on tolerance, geometry, batch size, and final hardness.
CNC Machining Challenges of X46Cr13
Machining X46Cr13 is manageable, but it has several difficulties that should be addressed before production. The material can work harden, produce burrs, wear tools faster than softer stainless grades, and become much harder after heat treatment. Thin features may distort, holes may lose accuracy after hardening, and polished surfaces may reveal scratches or inclusions. For this reason, an X46Cr13 CNC machining quote should consider not only material and cycle time, but also heat treatment, finish allowance, inspection, and possible secondary finishing.
Tool Wear and Cutting Heat
X46Cr13 contains enough carbon and chromium to make cutting more demanding, especially when carbide structures and hardness increase. Excessive cutting heat can damage tools, reduce surface quality, and create dimensional drift. Sharp coated carbide tools, stable feeds, proper coolant, and rigid setups are important. The goal is to cut cleanly rather than rub the material, because rubbing can harden the surface and make the next pass more difficult.
Challenge and Solution Table
A structured process plan helps reduce scrap and rework. The following table connects common machining problems with practical countermeasures.
| Machining Challenge | Why It Happens | Praktische Lösung |
| Fast tool wear | Carbon-chromium structure and higher hardness | Use coated carbide tools, stable cutting parameters, and coolant |
| Burrs on holes and edges | Tough martensitic stainless behavior and interrupted cuts | Add controlled deburring and avoid overly sharp unsupported edges |
| Heat-related size drift | Poor heat removal during aggressive cutting | Use coolant, reduce rubbing, and allow thermal stabilization |
| Distortion after hardening | Internal stress and phase transformation | Rough machine first, stress relieve if needed, leave finish allowance |
| Polishing defects | Surface scratches, inclusions, or tool marks | Specify finish direction, roughness target, and polishing sequence |
| Thread quality issues | Material strength and burr formation | Use correct tapping strategy, thread milling when suitable, and inspect with gauges |
Heat Treatment and Finish Allowance
Heat treatment is often the biggest difference between a simple quote and a reliable X46Cr13 production plan. If the drawing specifies final hardness, the supplier should decide which features are rough machined before heat treatment and which are finished after. For tight bores, sealing faces, bearing seats, or precision threads, leaving finishing allowance can prevent rejection after hardening. Stress relief may also be useful for parts with uneven wall thickness or heavy material removal.
X46Cr13 and Maraging Steel CNC Machinability Comparison
X46Cr13 and maraging steel can both be CNC machined, but they behave differently. X46Cr13 is a carbon-bearing martensitic stainless steel whose machining difficulty increases significantly after hardening. Maraging steel is usually easier to machine before aging and then gains very high strength through aging treatment. This difference is important because many buyers compare them only by strength or hardness, while the real manufacturing question is when the material becomes hard and how much the part changes during heat treatment.
Machining Strategy Difference
For X46Cr13, the common strategy is to machine in soft annealed condition, heat treat, then finish critical features if tight tolerances are required. For maraging steel, the common strategy is to machine most features before aging because the material is known for good machinability in the pre-aged state and relatively stable dimensional change during aging. Therefore, maraging steel may be more attractive for complex high-strength parts, while X46Cr13 may be more economical for stainless wear-resistant parts with moderate corrosion needs.
Machinability Comparison Table
The table below compares practical CNC factors rather than only material properties. This helps engineers choose the material based on production risk.
| Faktor | X46Cr13 Stainless Steel | Maraging Steel |
| Hauptzweck | Wear-resistant stainless parts with polishability | Ultra-high-strength parts with toughness and stability |
| Beste Bearbeitungsbedingungen | Soft annealed before hardening | Solution treated or pre-aged condition before aging |
| Heat treatment concern | Distortion and hardness increase after quench and temper | Aging response and final property control |
| Tool wear risk | Moderate to high, especially after hardening | Generally favorable before aging; difficult after peak aging |
| Korrosionsverhalten | Moderate stainless behavior | Usually needs environment review or protection |
| Cost level | Often lower than maraging steel | Usually higher material and process cost |
| Beste Passform | Pump parts, valve-related parts, shafts, guides, polished wear parts | High-load tooling, precision strong components, molds, fixtures |
Selection Summary
Choose X46Cr13 when the project needs a hardenable stainless steel with good polishability and wear resistance. Choose maraging steel when the project needs ultra-high strength, high toughness, and more predictable aging after CNC machining. Neither material is automatically better. The correct choice depends on load, corrosion environment, heat treatment route, tolerance, cost target, and inspection method.
Design and Quotation Points for X46Cr13 CNC Parts
A good X46Cr13 CNC machining project starts with a clear drawing. Because this material is often used for functional surfaces, missing information can lead to wrong assumptions. A 3D model may define geometry, but it does not always define hardness, surface roughness, heat treatment condition, burr limits, thread class, flatness, parallelism, or inspection requirements. These details are especially important when the part has sealing surfaces, sliding fits, polished areas, or features that must remain accurate after hardening.
Drawing Information to Include
The drawing should clearly separate general dimensions from critical features. This prevents unnecessary cost on non-critical surfaces while protecting the features that truly affect function. For example, a shaft outside diameter may need tight tolerance and fine roughness, while a clearance pocket may only need standard machining. This distinction helps the supplier plan tools, inspection, and finishing steps efficiently.
Useful Specification Checklist
The following items make quotations more reliable and reduce later engineering discussions. They are especially useful for custom X46Cr13 precision parts.
- Material designation and required standard, such as X46Cr13 or 1.4034.
- Required delivery condition or final heat treatment condition.
- Final hardness range and whether it applies to the whole part or only selected areas.
- Critical tolerances after heat treatment, not only before heat treatment.
- Surface roughness requirements for sealing, sliding, or polished faces.
- Thread specification, inspection method, and deburring requirements.
- Any flatness, straightness, concentricity, or runout requirement.
Inspection Planning
Inspection should match the function of the part. For X46Cr13 components, hardness testing, dimensional inspection, thread gauging, surface roughness measurement, and visual surface checks may all be relevant. If the part is heat treated, inspection after heat treatment is more important than inspection before it. For high-value components, first article inspection can help confirm the full manufacturing route before batch production.
Fazit
X46Cr13 is a hardenable martensitic stainless steel used for CNC machined parts that need wear resistance, polishability, moderate corrosion resistance, and controlled strength after heat treatment. It is suitable for pump components, valve-related parts, shafts, guides, seats, and precision wear parts, but it requires careful machining, heat treatment planning, and inspection. Compared with maraging steel, X46Cr13 is usually chosen for stainless wear performance, while maraging steel is selected for ultra-high strength, toughness, and dimensional stability after aging.
FAQ
Is X46Cr13 the same as 420 stainless steel?
X46Cr13 is closely related to 420-type martensitic stainless steel, but buyers should not treat all 420 names as automatically identical. Standards, carbon range, heat treatment condition, and supplier certificate can differ. For CNC machining, the safest approach is to specify X46Cr13 or 1.4034 on the drawing and confirm the material certificate before production.
Can X46Cr13 be CNC machined after hardening?
It can be machined after hardening, but the process becomes slower, more expensive, and more demanding on tools. For many precision parts, rough machining before heat treatment and finishing critical surfaces after heat treatment is more practical. Grinding or controlled finish machining may be needed for tight tolerance surfaces.
Is X46Cr13 good for corrosion-resistant CNC parts?
X46Cr13 offers moderate corrosion resistance, especially with proper heat treatment, polishing, and cleaning. It is not the best choice for highly corrosive or chloride-rich environments. If corrosion resistance is the main requirement, stainless grades such as 316 or another suitable alloy may be better. If wear resistance and hardness are also required, X46Cr13 becomes more attractive.
When should I choose maraging steel instead of X46Cr13?
Choose maraging steel when the part needs ultra-high strength, high toughness, and good dimensional stability after aging. Choose X46Cr13 when the part needs a hardenable stainless steel with wear resistance and polishability. Maraging steel usually costs more, so it should be justified by performance or manufacturing risk reduction.