• Investment Castings
• Permanent Mold Castings
• Plaster Mold Castings
• Sand Castings
• Die Castings
• Lost Foam Castings
• Shell Mold Castings
• Powder Metal

Foundry Associates, Inc. 6800 Pittsford-Palmyra Road

Suite 190  Cedarwood Office Park Fairport, NY 14450

Phone 585-421-9000  Fax 585-421-9333

FOUNDRY ASSOCIATES, INC. - CASTING TECHNIQUE COMPARISONS

INVESTMENT CASTING

Description

Metal mold makes wax replica. These are sprued, then surrounded with investment material, baked out and metal poured in the resultant cavity.

Metals

• Most all Castable Metals

Size Range

Fraction of an ounce to 200 pounds, up to 48”

Tolerances

± .005” per inch

Minimum ± .003”

Part Price 1 Lowest 5 Highest

5

Design Freedom 1 Lowest 5 Highest

5

Surface Finish

.63-125 RMS

*Draft Requirements None

**Normal Minimum Section Thickness Aluminum Alloy  .020”

Beryllium Copper        .030”

Stainless Steel  .050”

Carbon Steel               .050”

Ordering Quantities Any Quantity

***Normal Lead Times

Samples: 3-8 weeks (depending on complexity)

Production: 3-7 weeks (dependent on subsequent operations)

The above are generalities and should be used only as a rough guide. When in doubt, check with your local Sales Engineer. Often he will wish to evaluate two or more processes for a given part. He can elaborate on the above information as applied to your specific parts.

*Increase Draft with Depth

** Size and surface area influence minimum thickness

***This will vary widely depending on business conditions and foundry load.

POWDER METAL

Description

Metal powder is compressed in die barrel between moving upper and lower punches. Lower punch ejects part, which is then sintered and sized if close tolerance is required.

Metals

• Iron and Iron Alloys, Copper, Bronzes, Brass, 316 Stainless Steel, Monel

Size Range

Limitation on surface area-up to 20 square inches ferrous, higher with non-ferrous

Tolerances

Sized:             ± .0005” per inch

Unsized:        ± .004” per inch

Direction of pressing ± .005”

Part Price 1 Lowest 5 Highest

3

Design Freedom 1 Lowest 5 Highest

1

Surface Finish

Equivalent to 16-90 RMS in solid metals

*Draft Requirements Usually none

**Normal Minimum Section Thickness

.030” 0.090” (depending on density and length ratio)

Ordering Quantities

Usually 2,000 and up. Larger parts sometimes as low as 500

***Normal Lead Times

Samples: 6-14 weeks (depending on complexity)

*Increase Draft with Depth

**Size and surface area influence minimum thickness

***This will vary widely depending on business conditions and foundry load

PLASTER MOLD

Description

Cope and Drag Method (using fine plaster for mold and cores). Plaster slurry is poured onto pattern halves, allowed to set then mold is removed from pattern, baked, assembled and metal is poured into the resultant cavity.

Metals

• Aluminum, Brass, Bronze, Zinc, Beryllium Copper

Size Range

Normally up to 800 square inch area. Some foundries capable of going larger.

Tolerances

One side of parting line ± .005” up to 2 inches. Over 2 inches add ± .002” per inch. Across parting line

± .010”. Allow for parting line shift of ± .015”.

Part Price 1 Lowest 5 Highest

4

Design Freedom 1 Lowest 5 Highest

4

Surface Finish 63-125 RMS

*Draft Requirements External: 0? - ½? Internal: ½? - 2?

**Normal Minimum Section Thickness

.060”

Ordering Quantities

Aluminum: usually under 2,000. Copper Base: all quantities.

***Normal Lead Times Samples: 3-15 weeks

Production: 4-8 weeks

*Increase Draft with Depth

**Size and surface area influence minimum thickness

***This will vary widely depending on business conditions and foundry load

DIE CASTING

Description

Molten metal is injected, under pressure, into hardened steel dies.

Metals

• Aluminum, Zinc, Magnesium

Size Range

Not normally over 3 feet square. Some foundries capable of larger sizes.

Tolerances

± .0015” per inch. Not less than .002” on any one dimension. Additional .010” on dimensions affected by parting line.

Part Price 1 Lowest 5 Highest

1

Design Freedom 1 Lowest 5 Highest

2

Surface Finish 32-90 RMS

*Draft Requirements 1? - 3? Aluminum

½? -  2? Zinc

**Normal Minimum Section Thickness Aluminum

.050” Small parts.

.080” Large parts.

Zinc

.025” Small parts.

.040” Medium parts.

Ordering Quantities Usually 500 and up.

***Normal Lead Times Samples: 8-16 weeks

Production: 2-6 weeks

*Increase Draft with Depth

**Size and surface area influence minimum thickness

***This will vary widely depending on business conditions and foundry load

PERMANENT MOLD

Description

Molten metal is gravity poured into cast iron or steel molds, coated with ceramic mold wash. Cores can be metal, or sand.

Metals

• Aluminum, Brass, Bronze

Size Range

Limitation mainly foundry capabilities. Aluminum: Usually ½ pound to 100 pounds.

Tolerances

Aluminum: Min ± .010” up to 1 inch, or ± .015” if across parting line: add ± .002” each additional inch.

Iron: ± 1/32” all directions.

Part Price 1 Lowest 5 Highest

2-3

Design Freedom 1 Lowest 5 Highest

3

Surface Finish Aluminum: 150-200 RMS

*Draft Requirements Aluminum:

Outside: 2? Min. (3? Desirable) Inside: 2? Min. (4? Desirable)

Iron: Out: 3? In: 7?

**Normal Minimum Section Thickness

Aluminum: .100” for small areas, up to 3/16” for large areas. Iron: 3/16” for small areas, 1/4” normal.

Ordering Quantities Usually 500 and up.

***Normal Lead Times Samples: 6-14 weeks

Production: 2-6 weeks

*Increase Draft with Depth

**Size and surface area influence minimum thickness

***This will vary widely depending on business conditions and foundry load

RESIN SHELL MOLD

Description

Cope and Drag Method. Resin-coated sand is poured onto hot metal patterns, curing into bonded sand shell mold halves. These are removed from pattern, assembled with or without cores, and metal is poured into resultant cavities.

Metals

• Most all Castable Metals.

Size Range

Normal maximum 550 square inches usable mold area.

Tolerances

FERROUS ± .008” per inch up to 3 inches. Add ± .005” per inch over 3 inches.

NON-FERROUS

Under 1” ± .004-.006

Under 3” ± .005-.010

Under 6” ± .008-.013

Under 12” ± .015-.020

Add ± .005” to .010” across parting lines.

Part Price 1 Lowest 5 Highest

2-3

Design Freedom 1 Lowest 5 Highest

3

Surface Finish Non-Ferrous: 125-200 RMS

Ferrous:

200-350 RMS

*Draft Requirements Outside: 0-1?

Inside: 0-2?

**Normal Minimum Section Thickness 3/23” Non-Ferrous

1/8” Ferrous

Ordering Quantities Ferrous: Usually 250 and up

Non-Ferrous: Any Quantity

***Normal Lead Times Samples: 4-10 weeks

Production: 2-4 weeks

*Increase Draft with Depth

**Size and surface area influence minimum thickness

***This will vary widely depending on business conditions and foundry load

Description

Cope and Drag Method. Tempered sand is packed onto wood or metal pattern halves, removed from pattern, assembled with or without cores, and metal is poured into resultant cavities. Various core materials can be used.

Metals

• Most all Castable Metals.

Size Range

Limitation mainly foundry capabilities. All sizes.

Tolerances

± 1/32” up to 3 inches;

± 3/64” from 3 inches to 6 inches; ± 1/16” above 6 inches. Add ± .020 to ± .060 across parting line.

Part Price 1 Lowest 5 Highest

1-3

Design Freedom 1 Lowest 5 Highest

3

Surface Finish Non-Ferrous: 150-350RMS

Ferrous:

250-500 RMS

*Draft Requirements 1? to 5?

**Normal Minimum Section Thickness Non-Ferrous: 1/8”-1/4”

Ferrous: 1/4”-3/8”

Ordering Quantities All quantities.

***Normal Lead Times Samples: 2-6 weeks

Production: 2-4 weeks

*Increase Draft with Depth

**Size and surface area influence minimum thickness

***This will vary widely depending on business conditions and foundry load