P20 / 1.2311 Plastic Mold Steel
P20 / 1.2311 is a pre-hardened Cr-Mn-Mo plastic mold steel for injection molds and general plastic tooling. It is normally supplied at around 280-325 HB / 28-32 HRC, so many mold components can be machined and used without final hardening.
Typical Specifications
| Grade | Steel grade |
|---|---|
| Product | Plate / bar / block |
| Condition | Confirm by order |
| Standard | Confirm by required standard |
Key Features
Typical Applications
WhatsApp / Email / RFQ
Send grade, size, quantity and destination port. Our sales team will check stock, cutting service, weight and delivery time.
Procurement Summary
Equivalent / Grade Comparison
Equivalent names are practical procurement references. Final acceptance must be based on the agreed standard, actual MTC, hardness, ultrasonic testing requirement and application.
Key Properties
Properties are purchasing-oriented and should be confirmed against the required delivery condition.
P20 / 1.2311 Chemical Composition Comparison
P20 / 1.2311 is a Cr-Mn-Mo plastic mold steel. Chromium, manganese and molybdenum support through-hardness in pre-hardened mold plates and blocks. Buyers should confirm actual MTC chemistry, hardness and section size, especially for large mold plates where hardness uniformity matters.
Typical Applications
Available Service
Typical Delivery Condition
Delivery route depends on product form, mill practice, section size and the final mold requirement.
Heat-Treatment Guidance for P20 / 1.2311
P20 / 1.2311 is normally supplied pre-hardened and usually does not require final hardening before use. The values below are reference ranges for engineering discussion and must be confirmed against the supplier route and section size.
| Process | Reference Parameters | Buyer Notes |
|---|---|---|
| Stress relieving | 550-650°C; normally 1-2 hours after uniform heating; slow cooling in furnace or still air. | Used to reduce machining stress after heavy rough machining. |
| Annealing, if required | Approx. 710-740°C followed by slow furnace cooling. | Improves machinability if material is supplied by an annealed route; most commercial mold plates are purchased pre-hardened. |
| Hardening, special cases | Preheat 600-650°C; austenitize 840-870°C; quench in oil, polymer or controlled cooling depending on section size and distortion risk. | Final hardening is not the usual route for standard pre-hardened P20 mold plates. |
| Tempering | Approx. 540-680°C depending on hardness target; multiple tempering may be used depending on section and final requirement. | Typical working hardness for pre-hardened supply is approx. 28-32 HRC. |
| Nitriding | P20 / 1.2311 can be nitrided to improve surface wear resistance when required. | Consider nitriding based on mold application, polish requirement and dimensional tolerance. |
Typical Working Hardness by Application
| Application | Typical Hardness / Condition |
|---|---|
| Injection mold plate | 280-325 HB / approx. 28-32 HRC |
| Mold base / die holder | 280-325 HB |
| General plastic mold insert | Approx. 28-32 HRC |
| Nitrided wear surface | Surface hardness depends on nitriding process |
| Large mold plate | Confirm core/surface hardness uniformity by MTC |
P20 vs Plastic Mold Steels
For mirror-polish, corrosion-resistant or PVC/plastic corrosive environments, 1.2316 / 1.2083 / 4Cr13-type stainless plastic mold steels may be more suitable.
| Grade | Main Advantage | Limitation |
|---|---|---|
| P20 / 1.2311 | Economical pre-hardened plastic mold steel with good machinability | Not ideal for corrosion-resistant or mirror-polish molds |
| 1.2312 / P20+S | Better machinability | Lower polishability and toughness due to sulfur |
| 1.2738 / P20+Ni | Better large-section hardness uniformity | Higher cost |
| 1.2316 | Better corrosion resistance | Higher cost, different application focus |
| 1.2083 / 420-type | High polishability and corrosion resistance | Different hardening route and cost level |
| S50C / 1045 | Economical mold base / holder steel | Lower hardenability and wear resistance than P20 |
Buyer Checklist Before Ordering
- Grade and standard
- Product form
- Size and tolerance
- Hardness range
- Surface condition
- Machining allowance
- UT requirement
- MTC requirement
- Final mold application
- Polish / texture / nitriding requirement
- Export packing
- Destination port
- Delivery schedule
RFQ Information to Send
- Required grade: P20 / 1.2311 / 40CrMnMo7
- Product form
- Size
- Quantity
- Hardness requirement
- Surface condition
- Machining allowance
- UT requirement
- Destination port
- Delivery time
- MTC / packing / marking requirements
Supply and Processing Support
P20 / 1.2311 Plastic Mold Steel FAQ
1. What is P20 / 1.2311 steel used for?
P20 / 1.2311 is used for injection molds, mold bases, die holders, plastic mold plates and general plastic tooling components.
2. Is P20 / 1.2311 supplied pre-hardened?
Yes. P20 / 1.2311 is usually supplied in a pre-hardened condition so many mold components can be machined and used without final hardening.
3. What is the typical hardness of P20 / 1.2311?
Typical supply hardness is 280-325 HB / approx. 28-32 HRC, depending on mill practice and section size.
4. Is P20 / 1.2311 suitable for mirror-polish molds?
It has moderate polishability for general plastic molds. For mirror-polish or corrosion-resistant molds, 1.2316 / 1.2083 may be better.
5. What is the difference between 1.2311 and 1.2312?
1.2312 contains sulfur for better machinability, but the sulfur addition reduces polishability and toughness compared with 1.2311.
6. What is the difference between 1.2311 and 1.2738?
1.2738 is a nickel-modified P20-type steel with better large-section hardness uniformity, normally at a higher cost.
7. Can P20 / 1.2311 be nitrided?
Yes. P20 / 1.2311 can be nitrided when surface wear resistance is needed, subject to mold application, polish requirement and tolerance.
8. Does P20 / 1.2311 need final heat treatment?
Standard pre-hardened P20 usually does not need final hardening before use. Stress relieving may be considered after heavy rough machining.
9. What should buyers confirm before ordering P20 steel?
Confirm grade, size, hardness, MTC, UT requirement, surface condition, machining allowance and final mold application.
10. Is P20 / 1.2311 suitable for large mold plates?
It can be used for large mold plates, but buyers should confirm core/surface hardness uniformity and UT requirements before ordering.
Estimate Weight Before Inquiry
Calculate plate, round bar, flat bar or block weight, then send the result with your RFQ.
Calculation is for quotation reference only. Actual weight may vary by tolerance, cutting allowance and surface condition.
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Include grade, dimensions, quantity, destination country or port, required standard and surface condition.