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Questions tagged [casting]

29 questions
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1 answer

How do the dimensions of a ductile iron casting change as it cools?

I am designing a pattern for a sand casting. It has only one critical dimension which is a 4" inner diameter cylinder. If I use a 4" core, will the casting shrink away from the core? In other words will the inner diameter of the cylinder end up…
Wallace Park
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4 answers

What is the purpose of grid-like details on engine blocks?

It is common to find this kind of detailing and patterning on engine blocks and related parts. Older engine blocks display much more flatter and simple geometry and this kind of mold work must come with a considerable production cost. What is it's…
user15340
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6
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1 answer

What's the point of draft in sand casting

I know what pattern draft is and it's usefulness in removing castings from rigid moulds. That's the definition you can find anywhere. My problem is when you sand cast. Sand casting is the most common amateur metal casting technique, with lots of…
Paul Uszak
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5
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2 answers

What are 'inside' and 'outside' dimensions in reference to castings?

I am looking at a company-written standard for cast parts. The castings are blanks for driveshaft yokes, similar to what is pictured below. The standard defines general tolerances for the dimensions on the part, and it classifies them into two…
Trevor Archibald
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4
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Purpose and name of fine pitch marks on a cast metal part

I have seen this kind of mark on various cast metal parts. This is an image of the base casting of a hard disk drive made by HGST. What are these marks for? What are they called?
Alec Martin
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3
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Joining zinc components

I have a zinc lock box that looks like this: where there's a top and a bottom part. Notice that there're two interesting features (circled in red): After cutting it up slightly: The section view (of the right feature) looks like the…
John M.
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2
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1 answer

What is the highest-temp castable refractory cement available?

I very much ruined 3 $10 diamond hole saws making this ceramic insulator out of a firebrick and Ryobi drill press. Drilling out the large core took 1-2 hours and a lot of arm strength. Therefore, I will turn to custom ceramic shops or my own…
D Left Adjoint to U
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What is the characterising difference between a riser and a runner?

The image given below shows a bolster with a series of riser and runner. What I really do not understand is which is the riser and which is the runner. Also a detailed explanation to why multiple risers and multiple runners are being used will be…
gateprep
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What does "bedding-in" mean in casting technology?

I've heard this term used a lot in literature but I don't understand what the technique is they are referring to. Please help me out here.
Gaurav
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Does gravity have any effect on metal casting?

I wonder if the presence of a gravity field, makes any difference in the properties of the finished parts? That’s only if we can somehow, keep every other factor almost the same.
Michael
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(moulded) cast properties of the untreated surface

While my research about the untreated surface of moulded cast I read that the properties such as tensile strength, 0,2% proof stress and so on are different (much smaller) from the properties you can find in the tables. That’s because the samples…
tueftla
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What are the design principles for risers in sand casting?

Risers are added reservoirs used to feed liquid metal to solidifying casting. In the case of alloys that shrink during solidification (this is not the case of all alloys), one uses such reservoirs to make liquid metal available throughout…
Lucas
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Pouring aluminum into disks or cylinder shapes?

Is their a good method of making aluminum disks from molten aluminum? I have a large amount of aluminum castings and I would like to make rounds that could be chucked into my late and used to turn parts. Typically the castings are reduced to molten…
Rick
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Which materials can be used to make permanent casting molds for cast iron?

I am interested in comparing the different materials that can be used to make castings of cast irons, and therefore was wondering which material is commonly used/which materials can be used to make permanent casting molds (to be used specifically…
Sarah
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Is there any way to improve the strength of simple at-home aluminum/copper/brass castings (sand-casting hammers)

I'm just getting-into melting-down cans to make aluminum-based slingshots, hammers and the like. In my ignorance I didn't realize that copper/brass were also things that I could process which has left me hoping to learn: should I be looking to…
user23895
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