What is the difference between steel casting and iron casting?

Iron casting usually refers to gray iron, ductile iron and malleable iron, which is iron casting with carbon content upper than 2%. 

Steel casting usually refers to normal carbon steel and alloy steel, or called steel casting with carbon content lower than 2%. 

Therefore, no big difference considering from the chemical content and raw materials for cast iron vs cast steel. However, their physical properties have many differences. 

The advantage and disadvantage of Iron casting

The grey cast iron has good casting properties, good vibration damping, good wear resistance, good machinability and low notch sensitivity. However, its tensile strength and elongation are very low, so only can produce some metal parts with low physical requirements, such as protective cover, cover, oil pan, hand wheels, frame, floor, hammer, small handle, base, frame, box, knife, bed, bearing seat, table, wheels, cover, pump, valve, pipe, flywheel, motor blocks etc. As for the higher grades, grey cast iron can withstand greater load and a certain degree of tightness or corrosion resistance of the more important castings such as cylinder, gear, base, flywheels, bed, cylinder block, cylinder liner, piston, gear box, brake wheel, coupling Plate, medium pressure valve, etc 

The ductile iron and malleable iron have high strength, ductility, heat-resistance and toughness, so a wider application, in some cases can replace the carbon steel. However, its production technology is high, production process is more complex, and production cost is higher than normal grey cast iron and cast steel, therefore, there are more casting defects for ductile iron. There are many fields that ductile iron are using for, such as Pressure pipes and fittings, Automotive applications, Agriculture, road and construction applications, General engineering applications. 

The advantage and disadvantage of steel casting. 

One of the advantages of cast steel is the design flexibility, the designer of the casting have the greatest freedom of design choices, especially the complex shape and hollow cross-section parts. 

Steel casting has the metallurgy manufacturing flexibility and strongest variability, you can choose a different chemical composition and control, adapted to the various requirements of different projects. By different heat treatment choice in the larger context of the mechanical properties and performance, and good weldability and workability. 

Steel casting is a kind of isotropic material and can be made into the overall structural strength steel castings, thereby improving the reliability of the project. Coupled with the design and weight the advantages of short delivery time, price and economy has a competitive advantage. 

The weight range of steel castings is larger. Little weight can be only a few dozen grams of molten mold precision castings, and the weight of large steel castings up to several tons, dozens of tons or hundreds of tons. 

Steel castings can be used for a variety of working conditions, and its mechanical properties superior to any other casting alloys, and a variety of high-alloy steel for special purposes. To withstand high tensile stress or dynamic load of components, it is important pressure vessel castings in low or high temperature by the large and important part load key parts, in principle, should give priority to steel castings. 

However, the steel casting has comparatively bad shake-suction, wear resistance, mobility and the casting performance are compared bad with cast iron, moreover, the costs are higher than normal cast iron. 

Therefore, for iron casting vs cast steel, they have their own advantages and disadvantages, you should choose it according to your application and their physical properties.

Were honeycomb panels based on honeycombs?

Honeybees routinely build honeycombs, these possessing striking geometric features. 
Honeycomb panels - especially Aluminum - are routinely used in Aerospace. They have an incredible strength-to-weight ratio. 
I always wondering if there's a relationship between the honeycomb panels so often used in aircraft and the honeycombs built by bees.  Aerospace, yacht and motor racing designers use the phrase ‘Build lightness into your design’. Our honeycomb sandwich enables a designer to do just that. The honeycomb form provides stiffness, strength and light weight, whilst still offering a degree of flexibility. The technical terms for this are ‘high out-of-plane shear strength’ and ‘high out-of-plane compression properties’ in relation to other design options.
And that is why the plane panels are called honeycomb. The bees did not know it was stronger, but evolution selects for what works the best. Humans that are smart enough realize nature provides lots of similar well proven designs.

How to recycle old plastic bag

Wondering what to do with those plastic grocery bags? Here are a few interesting ideas for making the most of plastic bags. The following are some recycle method for you.

1. Reusing as bags

Reuse them for their initial purpose. Take them back to the grocery store for reuse in bagging your groceries. Refuse to accept new ones.

• Return your bags back to the grocery store for recycling. Most stores have a container to take these bags back and recycle them for you.

Consider no longer accepting plastic bags. The more that you continue to use the bags, the more stores assume you want them. By bringing your own bags with you, and by refusing plastic bags, you send a message that they're no longer wanted. However, be realistic. Some plastic bags prevent worse problems, such as leaking meat juices––use your common sense about minimizing their use.

2.Turn the bags into bin liners. Keep plastic bags around the house to replace trash can liners in the bathrooms, office and bedrooms. Keep them anywhere you have a small trashcan. Keep some in the laundry room to throw out pocket trash found in clothes and empty the lint filter in the dryer.

3.Store perishable food in plastic bags. Place food that perishes easily inside plastic bags before refrigerating.

4.Keep a stash of bags in each vehicle to help keep the car tidy. Hang one over a seat, arm rest, or simply keep it under a seat. Empty the bags regularly but only get rid of the bags if they're really filthy; otherwise, reuse them as many times as possible.

5.Donate the bags to your local charity shop or thrift store, library or flea market sellers. The bags can be used by people who borrow books, buy items or need to bring in items. Ask first though––quite a few charity shops have stopped accepting these bags for fear of contamination or unsavory objects inside them.

6.Make use of plastic bags for traveling. Plastic bags are light and not noticeable when shoved into your suitcase or backpack. They're ideal for the following:

• Keeping unwashed laundry separate from clean clothes in your bag.
• A makeshift shower cap if you don't want wet hair from showering.
• A ready-made garbage bag where none is available while traveling.
• Something to cover your shoes with if it starts raining heavily and your shoes can't get wet.
• Use the bags to help re-cart soggy laundry from a previous vacation home again.
• Something to collect and wrap souvenirs with.

7.Save your electronics from moisture when heading out of the house on a rainy day.