heat treatment
Used to improve comprehensive properties such as strength, toughness and wear resistance. If there is a target hardness/condition, please write it down in the order notes.
40Cr Alloy Steel
40Cr is a classic alloy structural steel, with advantages such as "high strength, good toughness, and more stable fatigue performance after quenching and tempering," suitable for functional parts that bear loads, withstand impact, and require longer service life.
Quote checklist: Upload your 3D model and, when available, a 2D drawing. Identify the required process, material, quantity, critical dimensions, finish, appearance standard, and target delivery date.
Key Material and Manufacturing Parameters
Engineering note: Values below are typical reference ranges. Final manufacturability, tolerances, material condition, surface finish, cost, and lead time depend on the drawing, geometry, quantity, and selected process.
Upload CAD files and mark critical features for an engineering review before production.
| Process | CNC Machining |
|---|---|
| Material grade | Alloy steel 40Cr (alloy structural steel) |
| Applications | Small batch processing of load-bearing structural parts, shafts, gears, connectors and high-load functional parts |
| Machining tolerance | ±0.2 mm |
| Minimum wall thickness | 1.0mm |
| Service temperature | 300-600℃ |
| Tensile strength | 450-1100MPa |
| Density | 7.7-8.5 g/cm³ |
| Heat treatment recommendations | If you need higher strength/wear resistance/fatigue life, it is recommended to describe the target performance and usage conditions in the remarks. Engineers can recommend appropriate heat treatment routes and processing sequences. |
| Finishing | Heat treatment, sand blasting, blackening, oxidation, nickel plating, chrome plating |
| Typical lead time | Related to structural complexity, tolerances, heat treatment and surface finishing options; clear lead time and expedited feasibility will be given after uploading the file |
Finishing
sandblasting
It is used to unify the surface texture and reduce the visibility of knife marks, and also facilitates the consistency of subsequent surface treatments.
Blackening
It is often used for surface rust prevention and appearance treatment of steel parts; it is recommended to provide reference when you are sensitive to color consistency and appearance standards.
Oxidation
Used to improve surface corrosion resistance and appearance consistency; if you require a specific appearance or corrosion resistance target, please indicate it in the remarks.
Nickel plated
Used to improve corrosion resistance and surface hardness/wear resistance; suitable for parts that require both appearance and corrosion resistance.
chrome plated
Used to improve surface wear resistance, corrosion resistance and appearance brightness; if it is a mating surface/sliding surface, please mark the key dimensions and coating requirements.
Why Choose Alloy Steel 40Cr (CNC Machining)
Strength and toughness are more balanced
Suitable for load-bearing, impact-bearing and functional parts requiring higher fatigue life, it is a common choice for upgrading from ordinary carbon steel.
Heat treatment can further strengthen
The overall performance can be improved through the heat treatment route; it is more friendly to high-load structural parts.
Adaptable shafts/gears/connectors
It is common in transmission and load-bearing scenarios; it is easier to achieve stable assembly results by cooperating with drawing tolerances and DFM review.
Surface rust prevention and appearance options
Supports sandblasting, blackening, oxidation, nickel plating, chromium plating and other solutions to facilitate the balance between corrosion resistance and appearance.
Recommended Applications
- Bearing/high load structure: Connectors, supports, transmission structures, etc.
- Shaft and gear parts: Requires higher strength, certain toughness and fatigue life
- Can be equipped with heat treatment strengthening: There is a need for further improvement in strength/wear resistance
- Requires rust prevention/appearance treatment: Optional blackening, oxidation, nickel plating, chrome plating, etc.
Consider Another Material or Process
- Strong resistance to corrosive environment: If there is long-term humidity/salt spray/chemical media, the stainless steel system should be evaluated first
- Extremely lightweight: Can evaluate lighter material systems such as aluminum alloy/titanium alloy
- Have special requirements for magnetic/electrical properties: It is recommended to select special alloys according to functional objectives
- Extremely demanding on dimensional stability and requires heat treatment: It is recommended to plan the route of “rough machining→heat treatment→finishing” in advance
Design and DFM Guidelines
- Heat treatment and deformation control: If heat treatment is required, it is recommended to state the target state in the remarks; a common practice is to rough-machin to leave a margin first, and then finish-machin the key surfaces after heat treatment.
- Thin wall/long thin parts: Long and thin shafts and thin-walled deep cavities are more susceptible to deformation; additional clamping datums, segmented processing, or structural thickening/reinforcement may be considered.
- Deep cavity and small rounded corners: Pockets that are too deep and fillets that are too small will increase the tool stress and processing difficulty; it is recommended to leave reasonable fillets and avoid extreme aspect ratio features.
- Holes/Threads and Fits: It is recommended that the tolerances and benchmarks of assembly holes, positioning holes, and mating surfaces be clearly stated in 2D drawings; if mating is after plating, please indicate the plating requirements and key dimension strategies.
- Rust Prevention and Appearance Standards: If the parts have a long transportation/storage period or the environment is humid, it is recommended to choose blackening/oxidation/nickel plating/chromium plating and other solutions, and clarify the appearance surface and allowable defect standards.