ADC12 Aluminum Alloy -Japan's Standard Die Casting Alloy

ADC12 (Japanese Industrial Standard JIS H5302) is the most widely specified aluminum die casting alloy in Japan and throughout the Asian automotive and electronics supply chains. It is roughly equivalent to the North American A383 alloy (ASTM B85), sharing a similar composition range but conforming to JIS chemistry limits and inspection requirements that Japanese OEMs require for material certification and supply chain traceability.

KastMfg has extensive experience producing ADC12 die castings for Japanese Tier 1 automotive suppliers, Japanese electronics OEMs, and their international facilities where ADC12 is the design standard. We provide JIS H5302 material certification with OES spectrometer data on every production batch.

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Chemical Composition

Element	Min %	Max %	JIS H5302
Silicon (Si)	9.6	12.0	Higher than A380 -better castability
Copper (Cu)	1.5	3.5	Lower than A380's 3.0-4.0%
Iron (Fe)	-	1.3	Reduces die soldering
Zinc (Zn)	-	1.0	-
Magnesium (Mg)	-	0.30	-
Manganese (Mn)	-	0.50	-
Nickel (Ni)	-	0.50	-
Tin (Sn)	-	0.20	-
Lead (Pb)	-	0.20	-
Aluminum (Al)	Balance	-	Base metal

Per JIS H5302. Note the silicon range 9.6-12.0% versus A380's 7.5-8.5% -this higher silicon is the primary compositional difference.

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Mechanical Properties (As-Cast HPDC)

Property	ADC12	A380 (reference)
Tensile strength	310 MPa (45,000 psi)	317 MPa
Yield strength	160 MPa (23,200 psi)	159 MPa
Elongation	2.5%	3.5%
Hardness	85 HRB	80 HRB
Shear strength	180 MPa	190 MPa
Impact strength	3 J	4 J

ADC12 is marginally harder than A380 (85 vs 80 HRB) due to the higher silicon content. Tensile strength and yield strength are essentially equivalent. The lower elongation (2.5% vs 3.5%) is a direct consequence of higher silicon increasing the volume fraction of the brittle eutectic silicon phase.

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Physical Properties

Property	ADC12	A380
Density	2.74 g/cm³	2.71 g/cm³
Thermal conductivity	96 W/m·K	96 W/m·K
Electrical conductivity	25% IACS	27% IACS
Coefficient of thermal expansion	21.0 μm/m·°C	21.1 μm/m·°C
Melting range	515-580°C	540-595°C
Casting temperature	640-700°C	620-680°C
Modulus of elasticity	71 GPa	71 GPa

ADC12's lower liquidus temperature (first solidification begins around 580°C vs 595°C for A380) contributes to its slightly better fluidity at equivalent casting temperatures.

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Why ADC12 Exists as a Separate Designation from A380

ADC12 and A380 are compositionally similar enough that engineers sometimes ask why separate designations exist. The answer is supply chain standardization, not technical differentiation.

The Japanese Quality System Requires JIS Certification

Japanese OEMs -Toyota, Honda, Denso, Aisin, and their supplier networks -specify materials by JIS designation. A380 is an ASTM designation; specifying A380 on a Japanese drawing does not automatically convey the same traceability, certification format, and quality inspection requirements as specifying ADC12 to JIS H5302.

When a Japanese customer specifies ADC12, they expect:

• Chemistry certification to JIS H5302 limits (not ASTM B85)
• OES spectrometer report in the format their receiving inspection team uses
• Material traceability documented per their supplier quality manual
• Alloy ingot sourced to JIS-certified ingot specifications

KastMfg's ADC12 production follows these requirements. We source ADC12-specification ingot with JIS certification from qualified suppliers, verify chemistry by OES on every melt, and provide material certificates in the format required by our Japanese customers.

Compositional Differences Matter at the Margin

The silicon range difference (ADC12: 9.6-12.0% vs A380: 7.5-8.5%) is real and has practical process implications:

Fluidity: ADC12's higher silicon extends the eutectic region, improving melt fluidity at equivalent temperatures. In complex automotive castings with multiple thin-wall sections, this provides marginally more reliable fill compared to A380.

Casting soundness: Higher silicon reduces solidification shrinkage slightly, contributing to marginally lower porosity levels in equivalent geometry. For automotive engine and transmission castings where internal soundness matters, this is a genuine -if small -advantage.

Surface finish: ADC12 produces a slightly finer as-cast surface texture than A380 due to the finer microstructure at higher silicon. In practice, this difference is visible at 10x magnification but imperceptible to touch.

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ADC12 in the Automotive Supply Chain

ADC12 is particularly dominant in automotive applications sourced through Japanese and Korean OEM programs:

Engine and Drivetrain

• Engine block end covers and cam covers
• Transmission and gearbox housings
• Oil pump bodies and filter adapters
• Water pump housings
• Throttle body housings
• Intake manifold lower sections
• Timing belt/chain covers

Chassis and Braking

• ABS/ESC modulator housings
• Brake master cylinder bodies
• Caliper anchor brackets
• Power steering pump housings and reservoir caps

HVAC and Thermal

• A/C compressor housings and front covers
• Heater blower motor housings
• Coolant distribution manifolds

EV / Hybrid Specific

• DC-DC converter housings
• OBC (onboard charger) structural housings
• HV junction box bodies
• BMS (battery management system) enclosures

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ADC12 in Electronics Manufacturing

Japanese electronics OEMs specify ADC12 for:

Consumer Electronics Infrastructure

• Heat sink housings for consumer AV equipment
• Set-top box and streaming device chassis
• Audio amplifier and receiver chassis
• Camera and optical equipment bodies

Industrial Electronics

• PLC and industrial controller housings
• Variable frequency drive enclosures
• Power supply housings
• Motor driver enclosures

Telecommunications

• Network switch and router chassis
• Small-cell base station housings
• Industrial communication equipment enclosures

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Machining ADC12

ADC12's machinability is excellent -comparable to A380, with some practical differences:

Chip formation: Higher silicon produces shorter, more brittle chips than A380 in most operations. This is generally beneficial -short chips are less likely to wrap around tooling or jam CNC chip conveyors. ADC12 tends to produce finer chip fragmentation in drilling and tapping.

Tool wear: The higher silicon content (9.6-12.0%) increases abrasive wear on cutting tools compared to lower-silicon alloys. KastMfg uses coated carbide (TiAlN or AlTiN coating) on ADC12 programs for drilling and milling, and PCD (polycrystalline diamond) tooling on high-volume boring operations for extended tool life.

Surface finish: ADC12 produces slightly better as-machined surface finish than A380 on facing and boring operations due to the finer microstructure. Ra 0.8-1.6 μm is achievable on precision bores without supplementary honing.

Thread forming vs thread cutting: For tapped holes in ADC12, KastMfg recommends thread-forming taps over cutting taps where hole geometry allows. Thread forming produces a stronger thread by cold-working the material, avoids chip entrapment in blind holes, and extends tap life significantly in the abrasive ADC12 alloy.

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Surface Finishing for ADC12

Finish	ADC12 Suitability	Notes
Shot blasting	Excellent	Standard preparation
Powder coating	Excellent	All RAL/Pantone colors
E-coating	Excellent	Full internal coverage
Chromate conversion	Good	Conductivity, pre-paint treatment
Type II anodizing	Functional	Moderate appearance quality due to silicon
Type III hard anodizing	Functional	Wear resistance applications
Chrome/nickel plating	Not recommended	Zinc preferred for electroplating

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ADC12 vs A380 -When Does the Choice Matter?

For the majority of industrial and commercial applications, ADC12 and A380 are fully interchangeable. Both alloys produce castings with equivalent dimensional accuracy, surface quality, and mechanical performance for general-purpose engineering uses.

The choice matters specifically when:

Specify ADC12 when:

• Customer drawing or specification calls out ADC12 or JIS H5302 by name
• Program is in a Japanese or Korean OEM supply chain requiring JIS certification
• Maximum castability in complex thin-wall automotive geometry is needed
• Casting soundness at the margin matters (automotive engine components)

A380 is equally suitable when:

• North American or European customers with ASTM-based specifications
• General industrial, commercial, and consumer applications
• Programs where the slight machinability advantage of A380 (lower silicon) matters

KastMfg maintains both ADC12 and A380 stock and can supply either alloy with the appropriate material certification format.

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Quality and Certification for ADC12

Material certification: Every ADC12 melt is verified by OES (optical emission spectrometer) to JIS H5302 limits. We issue material certificates showing actual chemistry versus specification limits, melt batch number, and production date. Certificates are in English and available in Japanese format for customers requiring Japanese-language documentation.

IMDS data: ADC12 IMDS (International Material Data System) data is available for automotive customers submitting parts to OEM material databases. KastMfg maintains current IMDS entries for ADC12 alloy per JIS H5302.

REACH / RoHS: ADC12 per JIS H5302 conforms to EU REACH regulation (no SVHC substances above threshold). RoHS compliance declaration available.

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Equivalent International Designations

Standard	Designation	Notes
JIS H5302 (Japan)	ADC12	Primary designation
ASTM B85 (USA)	A383.0	Closest equivalent -not identical
EN 1706 (Europe)	EN AC-47100	Approximate equivalent
BS 1490 (UK)	LM20	Approximate
ISO 3522	AlSi11Cu3 (Fe)	International equivalent

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Frequently Asked Questions

Is ADC12 the same as A383?

They are closely similar but not identical. A383 (ASTM B85) has a silicon range of 9.5-11.5% versus ADC12's 9.6-12.0%, and different limits on some trace elements. In practice, most A383 production would pass ADC12 analysis limits and vice versa, but the certifications are issued to different standards. For Japanese OEM programs requiring JIS H5302 certification, KastMfg supplies to ADC12 with JIS documentation.

Can KastMfg supply material certificates in Japanese?

Yes. For Japanese-language supply chains, KastMfg can issue material test certificates (Japanese-language material certificate in Japanese format with JIS H5302 reference. Contact us when submitting your RFQ to request Japanese-format documentation.

What is the ADC12 minimum order quantity?

There is no formal minimum. ADC12 programs follow the same MOQ structure as all KastMfg programs: prototype quantities from 50-100 pieces, production minimum runs of 500-1,000 pieces depending on complexity. Annual programs of any volume are accommodated.

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ADC12 die casting inquiry: yaoqingpu1983@gmail.com | +86 138 1403 4409 | No.6, Rungu Road, Nanjing, China