Questions tagged [metals]

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2answers
33 views

The behavior of the stress-strain curve of metal, containing a void

Let's assume that in a metal sample without any dislocation, there is a void. Then we conduct a uniaxial tensile test. (1) How does the stress-strain curve change, when the size of the void increases? ...
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0answers
21 views

Should I use brass compression fitting on brass tube?

I would like to use brass compression fitting on brass tube, I am confused because I have seen all the fittings that are used for copper and steel tube only. Is there and disadvantages?
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1answer
75 views

Hansel-Spittel equation parameter determination

I am currently learning how to determine the Hansel-Spittel equation parameters. The equation has following form: $$\sigma= A \cdot e^{m_1\cdot T}\cdot(\epsilon^{m_2})\cdot \exp\left(\frac{m_4}{\...
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11 views

Thermal expansion during the course of melting (in metals specifically)

The question is with regards to Thermal Expansion at the point of melting. My basic understanding is that a material will generally undergo linear thermal expansion until some phase change occurs (...
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1answer
16 views

How can we tell if a press mold need more stages?

I was asked to design a simple press mold for a 0.5mm sheet metal part. It has some small but rather deep sinks (5-7mm) which has made me wondering if it can be done in a single stage or it needs more ...
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2answers
57 views

How were these candlesticks made in the 1800s?

"Candlesticks" for this question are really just a stand-in for axisymmetric silver, brass, etc structures, possibly hollow and made of thin sheet material? Examples: From my research, today we ...
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1answer
32 views

Bendable flaps on sheet metal

I'm trying to cut some bendable flaps on aluminium sheets for hooking/clipping onto some fabric. The flaps I have in mind look like this: Are these common features? Does anyone know the geometry of ...
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1answer
43 views

Metallic flow behavior under eccentric loading conditions

So, I did a quick search around and didn't seem to find anything regarding this, so I thought perhaps I should just ask a question. Metals are malleable and will generally flow/deform if you roll it ...
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0answers
11 views

Will expanding metal disrupt my motion sensor?

I am trying to install a door motion sensor in a environment that will get very hot for our work. So the door could heat up to temperature of 150-200°F. We built the frames and door to handle the ...
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1answer
26 views

what design features allow a milling machine to withstand lateral pressures against the bit

I need to cut a slot 4mm wide by 25mm long in aluminum tube with a 2.2mm wall thickness and a 35mm O.D. The tube is 250mm in length. It seemed a drill press with a fluting bit might suffice for this ...
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1answer
34 views

Effect of annealing on the defects

What is the effect of annealing on the defects present in the sample? Does it remove defects in the sample? Is there any chance that due to annealing the point defects present in the sample combine to ...
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2answers
27 views

Mounting an antenna base on a roof using only double sided tape?

I want to put a vertical antenna on top of my roof. The antenna is basically 4 meters of PVC pipe and 5 meters of 19mm aluminium tubing. The roof at my house is corrugated sheet metal, and I want to ...
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1answer
34 views

Creep behavior in metals

If creep behavior can begin at 0.6T(melting) but, hot working for a pure metal starts at 0.4Tm, what is the explanation for this?
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1answer
69 views

What mechanism is available to rotate a metal piece on another metal piece?

I am trying to find some type of mechanism where I can have a smooth but not too stiff rotation between two metal pieces. I was thinking of putting a shoulder screw through the pieces (the pieces will ...
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0answers
31 views

How to produce aluminium powder by E. J. Hall method

I have watched videos on YouTube producing Aluminum powder by mechanical methods. Like this one. It uses Aluminum foil and coffee grinder: There are similar videos which use the same basic method but ...
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1answer
914 views

Arc-welding 2mm thick steel at an angle without burning-through

I'm learning a bit of stick welding since I keep needing it for certain projects. Total beginner. The latest thing I decided to make is a table similar to this one: The material is 2mm thick ...
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0answers
26 views

Steel Worm/Steel Wheel vs Steel Worm/Bronze Wheel

I have a question regarding worm drives, specifically double-enveloping types: Do steel worm/steel wheel combinations last longer than steel worm/bronze wheel or steel worm/brass wheel combinations? ...
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1answer
141 views

What are these metal cylinders often found in the streets of London?

I often find these metal cylinders in the streets of London: a silver-colored tube with a round tapering at one end and a hole with no thread at the other. What are they?
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2answers
47 views

Best way to dent a pipe from the inside?

I am currently trying to redesign a pipe with 2 dents from the inside. What is the best way to manufacture something like this, also how would i go about describing this process in a drawing? In the ...
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1answer
43 views

What's the best material to use for my project

I need to get a piece of stiff material cut and drilled for a project I'm working on. It has the following requirements: 1.6mm thick should be stiff (similar to PCB material, aluminum, fiberglass) ...
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2answers
159 views

Why not build container ships from plastic?

This may sound crazy but bear with me. I was thinking about why cargo ships are built from such heavy material as steel, while smaller boats are often made of plastics. I know cargo ships carry a lot ...
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2answers
410 views

What metal thickness and/or type is needed to support 100kg load?

I'm making a prototype that will have some load cells mounted approximately where the arrows are pointed in the image. The prototype will hold up to 100kg of load/force in the marked location thus I ...
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0answers
88 views

Calculating diameter of steel rod required to not bend over a given length

I want to use steel (or other material) rods to support weight over a 900mm cavity. The weight that needs to be supported is technically unknown, but I'd specify some rough guidelines as: 100KG (max) ...
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1answer
91 views

Tapping small hole on titanium

So I want to tap a super small hole on grade 5 titanium alloy with M1.8x0.2 (which should be possible according to this Quora's answer. But is there any tap available for me to do this job? I mean M1....
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3answers
181 views

How to increase maximum rotational speed limit of a reduction gearbox?

Reduction gearboxes made of machine steel gear have a maximum limit to prevent changing their physical properties (softening). They change their properties as a result of the temperature increase ...
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1answer
53 views

Glue metal bolt to nylon hole [closed]

What type of glue is best used to glue stainless steel bolt (not screw) used as self tapping to a hole (no thread) in a 3d printed nylon (polyamide) part? It will be an M2 metric bolt.
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1answer
5k views

Galvanized Steel (Zinc Plated Steel) vs Stainless Steel

Zinc Plating is known for its ability to prevent most corrosion, and it is done by just dipping a metal in hot pool of zinc and letting it cooldown. Meanwhile, stainless steel, an alloy that is ...
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2answers
156 views

What grade of titanium are “memory titanium” glasses made of?

I've worked with different grades of titanium. Mostly with grade 5, and also grade 1 which is ductile. I know that some glasses are made of titanium and are called "memory titanium", I guess because ...
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1answer
180 views

With which parameter can you specify whether a metal is ductile or brittle

I have to do a durability approval of feather key (shaft-hub connection) and the formulas are dependent if the shaft respectively the hub is ductile or brittle. But what is the decision about to say ...
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1answer
443 views

What is the most corrosion resistant 55HRC stainless steel?

55 HRC is a very high hardness, even for steels. Ideally the corrosion resistance of the steel would have to match AISI 316L or be even better. Qenched stainless steel can go to 55HRC. Even to 65 ...
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1answer
173 views

How to calculate the bending resistance of a square metal bar?

I have an old bend/twisted wooden door. It has some character to it so I want to keep it and add square metal bars to straighten it. I have provided a sample drawing of the door and where it is ...
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1answer
37 views

Can chemical vapor deposition chambers be used to lay down thick layers of metal?

Can CVD Chambers be used to lay down thick (~1 mm) layers of metal?
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2answers
191 views

Why did the Soviet Alfa-class submarines have a titanium hull?

My limited knowledge in engineering tells me: Titanium is expensive, stronger and heavier than aluminium, lighter and weaker than high yield steel. The most significant advantage of titanium is the ...
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1answer
198 views

Which materials we can use for storing liquid nitrogen?

What are the materials we can use for the long-term storage of 30~liters of liquid nitrogen with composition and grade, along with the thickness of the sheet and storage capacity? Can we use any ...
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6answers
795 views

How to create an airtight connection between Stainless Steel and PTFE?

I have these two parts shown below, the bottom cylindrical part is stainless steel, the rectangular upper piece is PTFE (Teflon). The SS prongs from the lower part need to insert into the holes of the ...
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2answers
2k views

What's the difference between tempering and aging?

The processes sound really similar; I'm asking with respect to Martensite processing. Essentially the difference between Tempered martensite and Aged martensite for Steels
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1answer
532 views

What is strain hardening exponent?

Hardening leads to a material being more brittle.However I can't understand what is strain hardening or strain hardening exponent.Please explain why hardening leads to brittleness also in this answer ...
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2answers
108 views

38CrNiMoAlA: Does it even exist?

I have some plungers made of 38CrNiMoAlA. Their required hardness to be achieved via quenching/tempering is 51 HRC. I've scoured our technical order for heat treatment of steel alloys but the material ...
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0answers
40 views

Find electronics in wilderness; or, “I dropped my cell phone in the woods!”

Imagine I was working in the woods and dropped my cell phone somewhere in a large area where it is now hidden beneath dense vegetation. By calling it I confirm that either it has powered off or its ...
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1answer
109 views

How Can I do punching of 0.22mm in stainless steel sheet (Sheet thickness 0.5mm)

Wanted to press punching of 0.22mm dia (Bottom) and on (top) 0.6mm dia Please suggest how can I make such die?
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1answer
143 views

Optimal size and shape for a steel target?

Problem I'm building a steel target for long-range rifle shooting. For those unfamiliar, the purpose of the steel is to produce a loud "PING" when the bullet strikes the target. It's very fun. Since ...
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3answers
63 views

Support columns inside metal tubing

Does structural metal tubing (e.g., either as HSS, or in space frames, or even motorcycle/bicycle frames) ever come with any small metal rods or columns inside of the tubing itself? While it might ...
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1answer
63 views

Coating gold on to sunglasses lenses?

Recently I have been trying to find out more about the process that is used to coat glasses lenses with gold. I asked about it in another forum last night and I was directed here. I initially thought ...
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1answer
133 views

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?
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2answers
157 views

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 ...
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1answer
2k views

Sheet Metal Bending: stuck on calculating the minimum radius required

I'm used to calculate the minimum radius required for bending operations on both aluminum and steel sheets, given the following parameters: https://imgur.com/a/7akHC Problem statement: For a sheet ...
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1answer
49 views

What considerations should I take when flame-hardening a wheel?

I'm currently trying to figure out whether or not we can flame-harden a steel wheel which was supplied with a lower hardness than expected. I'm worried, however, that flame-hardening can either deform ...
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3answers
179 views

I am looking for some basic mechanical parts to build structures(prototypes)?

I am looking for something like this to make my robot ideas as prototype. But I don't know it's name! Also if there are better options I will happy to know.
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1answer
384 views

Can a Plasma Cutter use for melt metals?

Can a Plasma Cutter use for melt metals like Iron, Brass, Stainless Steel ect, ?. Particularly for molding purposes. If can't, is there any other electric item that doesn't use gases (Acetylene, ...
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2answers
115 views

Is there a drill adaptor or attachment tool for cut a metal solid cylinder

I need to cut a 7mm solid Aluminium plug (Non-hollow and non-threaded) to replace a part in my car. Is there a simple drill adapter tool to cut a solid metal cylinder (Plug) from an Aluminium mass ? ...