INVESTMENT CASTINGS

We supply castings to some of the largest manufacturing organisations and blue chip companies in the world.

This is due to our world class delivery capabilities, automated processes which reduce tolerances and a finished product which is an exact fit for purpose.

It is all part of our Texmo ‘right first time’ mission statement.

“WHEN OTHER COMPETITORS TURNED DOWN REQUESTS FOR QUOTES OF NEW COMPLEX DESIGNS, TEXMO PRECISION CASTINGS STEPPED UP AND DELIVERED 7 NEW COMPONENTS AS PART OF A WORLD’S FIRST PRODUCT”

 

LEAD ENGINEER @ FORTUNE 500 AMERICAN MANUFACTURER

WHAT IS INVESTMENT CASTING?


Investment casting is a manufacturing process in which a wax pattern is used to shape a disposable ceramic mold. Then this is usually cast with molten metal  This process can also be referred to as “precision casting” or “lost wax casting”.

These castings are used around the world in a wide range of products and industries. For example, investment casting plays a crucial role in the medical industry (such as artificial knee and hip joints) and the aerospace industry (landing components, safety components and much more).  We have answered more questions like this on our dedicated investment castings FAQ page.

WHY USE INVESTMENT CASTINGS?


Automated processes and razor sharp accuracy allowed by technology means that businesses get the precision needed from their parts, without extended costs for labour, materials and machinery. Using investment casting also ensures that uniform dimensions and quality are afforded to businesses across all of their cast parts.

See more about the process of investment casting here.

INDUSTRIES


Due to the benefits of investment casting and a wide range of potential geometries and materials, the process is well suited for a wide range of applications including gas turbine components (both IGT and aerospace), medical devices and equipment, sensors, valves, compression systems, automotive components, industrial equipment components, hardware, sports equipment, gears, and golf club heads.

We supply some of the largest manufacturing organisations and blue chip companies – exceeding expectations and further increasing our reputation as one of the world’s leading investment casting manufacturers.

MEDICAL

The biggest market for medical investment castings is undoubtedly the orthopedic sector. The items used in joint replacements (such as hip and knee) demand precision and the measurements must be delivered in painstaking detail.

Other applications within the medical sector usually include:

• Surgical instruments
• Components for spinal reconstruction
• Dental implants
• Coronary angioplasty stents

AERO

Within the aerospace industry, we have used our expertise in precision to supply flight data recorder housings and critical engine equipment.

Other items delivered through investment casting usually include:

• Exterior and interior sensors, motion control and actuation systems
• Hydraulic fluid system components
• Cargo systems
• Landing and braking components
• Bearing cages

GENERAL ENGINEERING

We have experience in providing precision castings for some of the world’s largest companies, in areas such as power tools, automotive, process automation, military and safety equipment.

The alloys we can cast and our process enables us to provide small runs to high volume requirements for critical applications. Our manufacturing processes have been built to ensure flexibility in batch sizes and adapt to part requirements across a broad spectrum.

MATERIALS


Although in theory you can use most metal alloys in investment casting, the most common materials our customers use are:

• Carbon steels
• Low alloy steels
• High alloy steels
• Tool steels
• Stainless steels
• Cobalt alloys
• Cobalt-chrome alloys
• Nickel alloys
• Nickel-copper alloys

The above materials can be used across most parts and industries, you can see more about each individual material on our dedicated materials page. You can also quickly see some of the technical qualities of each material in our table below:

Alloy Capabilities
Base Category Sub-Group Examples of commonly used Alloy types
Ferrous Carbon Steels Low Carbon Steels 1010 1020 1025
Medium Carbon Steels WCB 1030 1035 1045 1050
High Carbon Steels 1060 1090 1095
Low Alloy Steels Chromium Steels 52100
Chromium-Molybdenum Steels 4130 4140 4150
Nickel-Molybdenum Steels 4620
Chromium-Vanadium Steels 6150
Nickel-Chromium-Molybdenum Steels 4330 4340 8620 8630 8640 8650
High Alloy Steels
(Stainless Steels)
Austentic Chromium-Nickel Steels 302 303 304/304L 309 310 316
Ferritic Chromium Steels 409 431 436 439
Martensitic Chromium Steels 410 416 420 431 436 440A
Duplex Steels CD-4MCu CD3MN $50 $50 $50 $50
Precipitation Hardening Steels 15-5 17-4
Tool Steels Air Hardening Steels A-2 A-6 H-11 H-13 H-43 T-1
Oil Hardening Steels D-2 D-3 0-1 0-2 M-2 M-42
Water Hardening Steels S-1 S-4 S-5 S-7
Cobalt Cobalt Alloys Cobalt Alloys Co-3 Co-4 Co-6 Co-12 Co-31 Co-93
Cobalt-Chromium Alloys F-75 FSX 414 N-155
Nickel Nickel Alloys Nickel-Copper Alloys M35-1 Monel A Monel B Monel D Monel S Monel E
Nickel-Chromium Alloys Alloy B Alloy C Alloy X CW-2M Alloy 625
DOWNLOAD ALLOY CAPABILITIES TABLE PDF ↓

DESIGN


When it comes to the design of an investment casting, the following are the main considerations you will have to make:

Flatness and Straightness. Thick to thin sections should be avoided and the use of ribs can help contribute to a straighter and flatter part. Geometries adjacent to large flat planes should be angled to promote solidification and to help prevent cavitation from occurring and creating “sump” on the large flat surface. Try and use uniform thicknesses on flat surfaces where possible.

Blind holes. The depth of a blind hole should not exceed its width. Through holes are easier to cast than blind holes but depending on internal geometry or diameter may also require the use of ceramic cores. In some cases, especially with threaded holes, a secondary machining operation may prove most economical.

Draft angle.

Undercuts. Can increase the complexity of the wax tooling and in extreme cases require the use of ceramic cores which can increase the cost.

For guidance on the minimum required thickness of the walls, see the table below:

Minimum Wall Thickness
Alloy Type Inches Millimeters
Low Carbon Steel 0.070 1.8
High Carbon Steel 0.060 1.5
Low Alloy Steel 0.060 1.5
Stainless Steel – 300 Series 0.040 1.0
Stainless Steel – 400 Series 0.060 1.5
Cobalt Alloys 0.030 0.75
Average 0.053 1.3
DOWNLOAD DESIGN TABLE PDF ↓

FINISHES

Our castings can be finished in various ways, if required by the customer. These may include:

• Polished (Electro, Hand and Vibro)
• Coated (Powder, Nickel, Zinc, Black oxide)
• Painted

There is also the option to add certain textures to the product throughout the process.  Our surface finishes page describes the options in more detail.

TOLERANCE

Tolerance capability is dependent on the linear size of the dimension and the geometry of the part but investment casting can hold tolerances as low as 0.003” (76 microns) without the need for additional processes.

There is a shrinkage factor present, but for the most part this can be predicted and allowed for within the prototyping and process. Typically, the dimensional accuracy of investment casting far exceeds the minimum required for the product.

Inches
Nominal Dimension Zone 1 Zone 2 Zone 3 Zone 4
0.00 0.39 0.010 0.014 0.020 —–
0.39 0.63 0.011 0.015 0.021 —–
0.63 0.98 0.012 0.017 0.023 —–
0.98 1.57 0.013 0.018 0.025 —–
1.57 2.48 0.014 0.020 0.028 —–
2.48 3.94 0.016 0.022 0.031 —–
3.94 6.30 0.017 0.024 0.035 0.047
6.30 9.84 0.020 0.028 0.039 0.055
9.84 15.75 0.022 0.031 0.043 0.063
Millimeters
Nominal Dimension Zone 1 Zone 2 Zone 3 Zone 4
0 10 0.26 0.36 0.52 —–
10 16 0.28 0.38 0.54 —–
16 25 0.30 0.42 0.58 —–
25 40 0.32 0.46 0.64 —–
40 63 0.36 0.50 0.70 —–
63 100 0.40 0.56 0.78 —–
100 160 0.44 0.62 0.88 1.20
160 250 0.50 0.70 1.00 1.40
250 400 0.52 0.78 1.10 1.60
DOWNLOAD TOLERANCE TABLE PDF ↓

RAPID PROTOTYPING


We can produce 3D printed wax models in days. From a 3D model we can cast parts in an incredible 7 days. This can significantly reduce the time is takes from inception to delivery on your parts. Rapid prototyping does away with the need for tooling required to inject wax patterns and opens the process up to using a broad spectrum of materials rather than the narrow amount usually associated with wax injection moulding.

For more information on the benefits of rapid prototyping, see our guide here.

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