A Comprehensive Guide to Die-Casting Mold Acceptance Standards: 9 Key Acceptance Criteria, from Mold Materials to Finished Product Inspection

1. Why Does the Acceptance of Die-Casting Molds Determine the Upper Limit of Product Quality?

The material, hardness, cooling system, and ejection system design of die-casting molds directly determine whether the product can meet dimensional tolerance, surface quality, and airtightness requirements. Mold acceptance is not a mere formality—a 10-mm deviation in the spacing of cooling channels can lead to thermal fatigue cracking, and an ejector pin that is just 1 mm smaller in diameter may break and jam during production.

These acceptance standards are based on the actual acceptance processes at front-line die-casting plants and cover the entire acceptance process, from the die itself (9 major inspection categories) to the finished products (structure, appearance, and other aspects). Each standard includes quantifiable metrics that can be directly used for on-site check-off acceptance.

Core Philosophy:Mold Acceptance = The first line of defense for zero-defect delivery. The clearer the acceptance criteria, the fewer rework and claims there will be.

2. General Framework for the Acceptance of Die-Casting Molds

The acceptance process for die-casting molds consists of two main stages:

• Phase 1: Acceptance of the Mold Itself(9 Major Categories) — Appearance → Material/Hardness → Type/Cavity → Production Method → Ejection System → Gating System → Cooling System → Slider System
• Phase 2: Acceptance of Finished Products(3 Major Categories) — Product Structure → Product Appearance → Other Requirements

After acceptance, it is also necessary to follow the heat treatment and maintenance specifications to ensure stable operation of the mold throughout its entire service life. For more information, The Complete Process of Die-Casting Mold Manufacturing ... For more information, please refer to the special feature articles on this site.

3. Mold Appearance Inspection: The First Step

3.1 Dimensions and Weight

Test Items	Receiving and Inspection Criteria
Mold Dimensions	Meets die-casting machine specifications and production safety requirements, and complies with the design drawings
Mold Weight	Suitable for the required die-casting machine specifications (if too large, clamping force will be insufficient; if too small, production capacity will be wasted)

3.2 Mold Markings

• Mark the TOP surface of each formModel Number
• Additional holes must be drilled on the A/B panelPseudolaric acid
• Non-standard labeling → Difficulty in subsequent traceability

3.3 Mold Surface

The mold surface must be free of severe impacts, dents, deformation, and rust. Surface defects directly affect the product’s appearance and the smoothness of the demolding process.

4. Inspection of Mold Material and Hardness: The Key to Determining Mold Life

4.1 Die Core Material

sports event	Standard Requirements	instructions
Mold Core Material	H13 Hot-Work Steel (2344 / 8407 / SKD61)	No weld repairs are permitted.
documentation	Proof of materials required + Heat treatment certificate	All are essential

Important Warning:Repair weld areas are prone to thermal fatigue cracks. During acceptance inspections, a visual inspection must be conducted, along with non-destructive testing as necessary, to ensure that repair welds are not concealed.

4.2 Hardness Requirements

Location	Hardness Range	instructions
Moren	HRC 46–52	Certificates of material composition and heat treatment are required.
Slider	HRC 46–52	Use heat-treatable steel for areas with adhesive; for areas without adhesive, use nitrided P20 or 45# steel.
Mold blank	LKM Standards / Other Standards	Must operate smoothly at high temperatures

4.3 Mold Life Benchmarks

Alloy Type	Mold life
aluminum	100,000–200,000 cycles
zinc alloy	300,000 cycles

If mold life falls short of specifications, there is a problem with the material or heat treatment. For a comparison of mold life and performance across different casting processes, please refer to Guide to Selecting Casting Processes.

5. Mold Type, Cavities, and Production Method

5.1 Mold Types

Type	Receiving and Inspection Criteria
Center Nozzle	Meet product quality requirements + comply with die-casting machine specifications
Eccentric Nozzle	Must meet the required die-casting machine specifications

5.2 Selecting the Number of Cavities

Number of cavities	Basis for Selection
1 Acupoint	Customer Requirements / Complex Product Design
2 Acupoints	Balance Between Supply and Demand
4 Acupoints	High-volume, simple-structure products
Other	Customization for Special Needs

5.3 Production Methods

way (of life)	Requirements
Automatic	The product must release automatically, not stick to the mold, and be easy for a robotic arm to grasp.
Semi-automatic	Can proceed with automated production
Manual	Use when automated production is not possible

6.1 Thimble Specifications

Test Items	Receiving and Inspection Criteria
material (that sth is made of)	Full-Hard Pin for Hot-Work Steel
Minimum Diameter	Not less than Φ4 mm
Load Requirements	Balanced force distribution during ejection, smooth operation
Top Trips	The highest point of the product as it is ejected from the mold insert must be at least 6 mm.
Sitong Top-Out	Do not perform a top-out move on the S-Tong

6.2 Returning the Ejection System to Its Original Position

• Standard Method:Return the retraction mechanism to its original position
• Springs can be used for small/simple molds, provided they meet the mold's service life requirements.

6.3 Thimble Clearance

Thimble Diameter	Fitting Clearance
> Φ10mm	0.04 mm
≤ Φ8 mm	0.02 mm

7. Acceptance of the Pouring System

Test Items	Receiving and Inspection Criteria
Side-Entry Injection	The gate location facilitates filling and trimming
The Bottom of the Flow Channel and the Corner	Rounded corners and a polished finish are required; sharp corners are not allowed.
Gate and Slag Ladle Length	No less than 2 mm, with appropriate depth
Gate Sleeve Dimensions	Complies with the specifications for die-casting machine pistons; if the trial-molding machine is not compatible with the production machine, a separate gate sleeve must be fabricated for trial molding.
Eccentric Nozzle	Must comply with die-casting machine specifications
Gate Cross-Sectional Area	The right size affects filling speed and porosity.
flow cone	Must be cooled separately

8. Cooling System Acceptance Testing

Test Items	Receiving and Inspection Criteria
Cooling Requirements	The cooling channels provide sufficient cooling for the product; the gate sleeves and runner cones must be cooled separately.
Channel Spacing	The spacing between the channels is approximately 40 mm
Distance from the cavity	Not less than 20 mm
Distance from the thimble screw	10mm
Connection Methods	The nozzle is connected directly to the mold core,Waterproof seal not available
Waterway Patency	The cooling water channels must be unobstructed and free of leaks.
Import and Export Markings	Import and export points must be clearly marked
Tooth Profile	Unless otherwise specified, use PT teeth.

Key Metrics:A 40mm spacing between channels, a distance of ≥20mm from the cavity, and a distance of 10mm from the ejector screw—these three figures are the "hard limits" for the acceptance of the cooling system.

9. Slider System Acceptance

9.1 Effects of Line-Position Movements

Test Items	Receiving and Inspection Criteria
Smoothness of Sliding	Smooth glide
Travel > 40 mm	The motion must be controlled by a hydraulic cylinder and a microswitch.
Diameter of the inclined guide post	Not less than Φ20 mm
Inner Slider	Avoid machining the inner slider as much as possible
Matching Segment Length	The section where the slide engages with the clamping plate shall be no less than 2/3 of the slide's length.

9.2 Steel for Sliders

Conditions	Steel Material Requirements
Glue application area	Hot-rolled steel
No-glue position	Nitriding of P20 or 45# Steel

9.3 Feed Trough and Hole Locations

• A material chute must be installed beneath the conveyor.
• Small holes are not ejected separately—they move to the next station along with the part, and the holes are machined afterward.
• Locating holes must be provided on the mold.

10. Acceptance of Molded Products: Final Verification of Mold Acceptance

10.1 Product Structure

Acceptance Criteria	(an official) standard
Dimensions (FAI/CPK)	After polishing: FAI passed & CPK > 1.67
Post-Processing Structure	Post-processing features not to be machined on the mold must be specified prior to mold opening.
Product Edges and Corners	Sharp corners are not allowed; R1 for protrusions, R2 for recesses

10.2 Product Appearance

Defect type	Receiving and Inspection Criteria
Cold-formed patterns or corrugations	Meets the customer's acceptance criteria or, after polishing, does not have
Edge-Trimmed Pieces	Easy to sand and machine
Crack	Not allowed
Pores or Shrinkage Holes	Not allowed
Peeling	Not allowed; after polishing, there are none, and the strength requirements are met.
Carbon Deposits	This is not permitted; the mold must undergo regular decarbonization.
mold sticking	Not allowed
Material Shortage	Not allowed

10.3 Other Product Requirements

sports event	Requirements
Demolding of Slender Holes	For slender holes with a diameter < Φ2.5 mm on a mold that will not be machined on-site but will undergo subsequent machining, SQCC must first approve the design, and positioning holes must be machined into the mold.
Parting line	Avoid dents as much as possible; do not chamfer the edges of frames or holes; ensure a 0.1 mm gap between the A and B panels.
Exhaust Slag Liner	There must be a sufficient number of slag pots; there must also be a slag pot at the end of the runner; when venting, avoid direct venting into the channel to prevent injury.

For finished product inspection, we recommend referring to Inspection Procedures and Acceptance Criteria in Aluminum Casting Production , to ensure that the acceptance results are objective and reliable.

11. Heat Treatment and Mold Maintenance Guidelines

11.1 Tempering and Heat Treatment

working procedure	Requirements
Stress-Relief Tempering	After rough machining the mold and before finishing, the following must be performed:
Quenching and Tempering	The heat treatment process must be strictly controlled, and the following steps must be performed: 3. Second Tempering Treatment

11.2 Mold Maintenance Schedule

Maintenance Milestones	Maintenance Procedures
Mass production of the new mold begins after 6,000 molds have been produced	Initial Stress-Relief Tempering
For every 10,000 molds produced in a batch	Stress-Relief Tempering
Approximately every six months of production	One mold disassembly and cleaning
Periodically	Carbon Deposits Removal Treatment

12. Die-Casting Mold Price Guide

The price of die-casting molds is influenced by various factors, including alloy type, complexity, number of cavities, steel grade, and number of sliders. The following price references are based on data from the Chinese market for 2025–2026 and are provided for use in evaluating procurement budgets.

12.1 Classification by Alloy Type and Complexity

Mould Type	Level of complexity	Price Range (USD)	Price Range (RMB)	Lifetime (die times)
Zinc Alloy Die-Casting Molds	Simple Single-Chamber	$3,000~15,000	¥22,000–108,000	500,000–1,500,000
Zinc Alloy Die-Casting Molds	Medium/Multi-chamber	$3,000~15,000+	¥22,000–108,000+	500,000–1,500,000
Aluminum Alloy Die-Casting Molds	Simple Single-Chamber	$5,000~20,000	¥36,000–144,000	20,000–30,000
Aluminum Alloy Die-Casting Molds	Moderately complex	$25,000~40,000	¥180,000–288,000	50,000–80,000
Aluminum Alloy Die-Casting Molds	Complex, multi-chambered	$50,000~80,000+	¥36,000–576,000+	100,000+
Aluminum Alloy Automotive Parts (Single-Chamber)	Moderately complex	$25,000~60,000	¥180,000–432,000	80,000–150,000
Aluminum Alloy Automotive Parts (4–8 Cavities)	Complex, multi-chambered	$80,000~200,000	¥57.6–1.44 million	80,000–150,000

12.2 Price Multiplier Based on the Number of Cavities

Number of cavities	Price Multiple	instructions
1 Acupoint	1x	standard of reference
2 Acupoints	1.4–1.6x	Shared components, not double
4 Acupoints	2.5–3x	Because of shared components, it is not 4 times
8 Acupoints	Higher	Sliders + Cooling + Balanced Flow Channels Increase Costs

12.3 Breakdown of Mold Costs

Cost Items	Percentage of total mold cost	instructions
Mold Design Fees	2%~3%	Large models: approximately 2%; small models: approximately 2.5–3%
Processing Fees	≤20%	CNC, EDM, heat treatment, polishing, etc.
Testing Fees	1%~2%	Inspection of Critical Dimensions, Male Core, and Mold Core
Tooling Costs (≤800T)	1%~1.5%	Molds under 800 metric tons
Mold Testing Fee (>800T)	2%	Molds rated at 800 metric tons or more
After-Sales Maintenance Fees (≤800T)	1%~1.5%	Debugging, Performance Tuning, Warranty Service
After-Sales Maintenance Fees (>800T)	2%	Large Molds
Shipping Costs	0.5%~1.5%	Depending on the customer's location
Taxes and Fees	Approx. 9%	After deducting the cost of materials, the company will cover the remaining amount.

12.4 Additional Factors Affecting Prices

Factors	Price Impact
Steel Grade: ESR H13 vs. Standard H13	ESR H13 is 20%–40% more expensive per kilogram
Slider/Sloped Roof	Increase mold cost by 15%–25% + 1–2 weeks of trial molding time
Mirror Polishing	Additional costs for surface treatment and polishing
Texturing/Etching	Additional Texture Processing Fees
Tight Tolerance Accuracy	Increase in processing and inspection costs

Quick Price Calculator:Aluminum alloy die-casting molds (medium complexity, single cavity) cost approximately 180,000–288,000 yuan; 4-cavity automotive part molds cost approximately 576,000–1,440,000 yuan. With a mold life of 80,000–150,000 cycles, the amortized cost per part is approximately 0.36–3.6 yuan.

For information on strategies for balancing minimum order quantities and mold costs for aluminum castings, please refer to Frequently Asked Questions and Lead Times for Die-Casting Factories . For mold investment during the prototype phase, we recommend referring to A Comprehensive Analysis of Aluminum Die-Casting Mold Design .

13. Summary Table of Acceptance Criteria for Die-Casting Molds

The following summary table consolidates all 9 major categories of mold acceptance criteria plus finished product acceptance criteria and can be printed directly for on-site acceptance inspections.

No.	Acceptance Categories	Test Items	Receiving and Inspection Criteria	Passed
一	Mold Appearance	Dimensions	Compliant with die-casting machine specifications and design drawings	☐
		weights	Suitable for the required die-casting machine specifications	☐
		Mold Markings	Mark each form with a form number; for A/B panels, also include the product name.	☐
二	Mold Material & Hardness	Mold Core Material	H13-class hot-work steel (2344/8407/SKD61), no weld repairs	☐
		Die Face Hardness	HRC 46–52, with heat treatment certificate	☐
		Slider Hardness	HRC 46–52	☐
		Mold blank	LKM standard or other standards; smooth operation at high temperatures	☐
		Mold life	Aluminum: 100,000–200,000 molds / Zinc: 300,000 molds	☐
三	Mold Type	Center Nozzle	Meeting Quality Requirements + Die-Casting Machine Specifications	☐
		Eccentric Nozzle	Meets die-casting machine specifications	☐
四	Mold Cavity	1 Acupoint	As requested by the customer	☐
		2 Acupoints	Production volume meets production needs	☐
		4 Acupoints	The complexity of the product structure allows for this	☐
		Other	Special Needs	☐
五	Production Methods	Automatic	Automatic demolding, non-stick, and easy to handle with a robotic arm	☐
		Semi-automatic	Capable of automated production	☐
		Manual	Use when there are no automatic conditions	☐
六	Ejector system	Thimble	Hot-work steel, fully hardened, ≥Φ4 mm, ejection ≥6 mm	☐
		Return to Position	Return mechanism resets (spring used only in small models)	☐
		Gap	>Φ10: 0.04 mm / ≤Φ8: 0.02 mm	☐
七	Gating System	Side-Entry Injection	Easy to fill and remove	☐
		Flow Channel	Rounded edges + polished, no sharp corners	☐
		Spout/Slag Ladle	Length ≥ 2 mm	☐
		Gate Sleeve	Meets the specifications for die-casting machine pistons	☐
		Gate Cross-Sectional Area	Just the right size	☐
八	cooling system	Cooling Requirements	Sufficient cooling channels; separate cooling for the gate sleeve and diverter cone	☐
		Channel Spacing	Spacing of approximately 40 mm; distance from the cavity ≥ 20 mm	☐
		Connection Methods	The nozzle connects directly to the mold insert; no O-ring is needed.	☐
		Flowability	The waterways are clear and free of leaks, and the inlets and outlets are marked.	☐
九	Slider System	Movements and Positions	Smooth sliding; use a hydraulic cylinder for distances greater than 40 mm	☐
		Angled Guide Pillar	≥Φ20 mm	☐
		Coordinating Section	≥ 2/3 of the line length	☐
		Steel	Hot-work steel with adhesive joints / P20 nitriding without adhesive joints	☐
十	Product Structure	Dimensions	FAI passed & CPK > 1.67	☐
		Post-Processing Structure	You'll know before tooling begins	☐
		Edges and corners	R1 is convex, R2 is concave, and there are no acute angles	☐
Eleven	Product Appearance	Cold-Formed Patterns/Corrugations	Meets acceptance criteria or, after polishing, shows no	☐
		Rough-cut pieces	Easy to sand	☐
		Crack	Not allowed	☐
		Pores/Shrinkage Holes	Not allowed	☐
		Peeling	Not allowed	☐
		Carbon Deposits	Not allowed	☐
		mold sticking	Not allowed	☐
		Material Shortage	Not allowed	☐
Twelve	(sth. or sb) else	Parting line	No dents; 0.1 mm gap between the A and B panels	☐
		Exhaust Slag Liner	Enough, with a bag of dregs at the end	☐
		Slotted Hole	<Φ2.5mm后加工，须定位孔	☐
Thirteen	Heat Treatment & Maintenance	Tempering	Stress relief after rough machining, followed by three cycles of quenching and tempering	☐
		Maintenance Schedule	First maintenance at 6,000 cycles / Tempering at 10,000 cycles / Cleaning every six months	☐

14. Frequently Asked Questions and Risk Disclosures

Risk 1: Substandard Materials Used in Place of Genuine Ones
Passing off P20 as H13 → Double verification via hardness testing and material certification. The thermal fatigue performance of P20 is far inferior to that of H13, and mold life may be reduced by 50% or more.

Risk 2: Insufficient cooling
Excessive spacing between cooling channels or excessive proximity to the cavity → thermal fatigue cracking. During acceptance inspection, it is essential to strictly adhere to the two mandatory requirements: a 40-mm spacing and a 20-mm distance from the cavity.

Risk 3: Insufficient engagement length of the slider
The clearance between the slide and the pressure plate is < 2/3 → Loose slide, flash. This directly affects product dimensions and appearance.

Risk 4: The thimble is too thin
Diameter < Φ4 mm → Prone to breakage and jamming. Production downtime + high maintenance costs.

Risk 5: Concealment of Repair Welds
High risk of thermal fatigue cracks in the repair weld area → Visual and non-destructive testing. Repair welds are the leading cause of premature mold failure.

For the complete process of selecting and purchasing automotive aluminum alloy castings, please refer to Die-Casting Services and Selection of Aluminum Alloy Castings . To learn more about the applications of the low-pressure casting process, please read Applications and Typical Uses of Low-Pressure Casting .

15. FAQ: Common Questions About Die-Casting Mold Acceptance

Q1: What is the required hardness for die inserts in die-casting molds?

The hardness requirements for die inserts in die-casting molds are as follows: HRC 46–52, H13-class hot-work steel (such as 2344, 8407, or SKD61) must be used, and certificates of material and heat treatment must be provided.

Q2: What type of steel is used for die-casting molds? Can P20 be used?

The mold core standard requires the use of H13-type heat-resistant steel(2344/8407/SKD61). When the slider has a rubber contact area, hot-work steel must be used; when there is no rubber contact area, P20 or 45# steel treated with nitriding may be used. P20 is not recommended for die inserts.

Q3: What is the typical service life of a die-casting mold—in terms of tens of thousands of castings?

The service life of an aluminum alloy die-casting mold is 100,000–200,000 cycles, The service life of zinc alloy die-casting molds can reach 300,000 cycles. Mold life is closely related to the material, heat treatment, and maintenance schedule.

Q4: What are the acceptance criteria for porosity in die-cast products?

Die-Cast ProductsNo air pockets or shrinkage cavities are allowed., and there must be no cracks, peeling, carbon buildup, mold sticking, or material shortages. Cold marks or ripples must comply with the customer’s acceptance criteria or be eliminated after polishing.

Q5: What is the maintenance interval for die-casting molds?

Mass Production of New Molds After 6,000 moldsAn initial stress-relief tempering treatment must be performed; thereafter,Per 10,000 moldsA stress-relief tempering treatment must be performed,Every six monthsThe left and right dies should be disassembled and cleaned once, and carbon deposits should be removed periodically.

Q6: What supporting documents are required for the acceptance of die-casting molds?

Requirements for the acceptance of die-casting molds:documentation(H13 Heat-Resistant Steel Material Report),Heat Treatment Certificate(HRC 46–52 Hardness Report),Mold Design Drawings,Dimension Inspection Record Formand other documents.