Unit Weight of M.S. Sheets

Dear Readers,

We are very often use the sheets and plates during construction activities. Sheet metal and plate metal are different forms of steel. The most notable difference between plate and sheet metal is the thickness of the products. Plate metal is thicker when compared to sheet metal.

In general thickness less then 5.99 mm is called sheet and more than 6 mm is called plates. Sheets can be measured in SWG or in mm (millimeter). Unit weight of Sheets is as follows.

Sheet metal is produced on an industrial scale by applying rolling, processing and drying techniques. Eventually it is the process of rolling that will decide whether a particular metal will be classified as sheet or plate. Rolling metal adds pressure which determines the overall thickness of the metal. If the metal is rolled thin then it is considered to be sheet and if it is thick then the metal can be classified as plate.

Weight of Pipes

 Dear Readers,

In continuation with my earlier post " Difference between Pipes & Tubes" , let us note the unit weight of Pipes, wall thickness and further details.

Pipes are specified based on the schedules. Normally we mention pipes as Standard pipes, Extra Strong, Double extra strong based on the applications and utilization purpose. However further it also classified technically on Schedules, subject to the wall thickness , These schedules starts from Schedule-10, Schedule-20, Schedule- 30 , Schedule-40, Schedule-60, Schedule-80, Schedule-100, Schedule-120, Schedule-140 & Schedule-160

Below Table shows the weights of Standard pipes, Extra Strong & Double strong. Theses are readily available in market.

Above table Wall thickness are mentioned in "mm" & Weights are in "Kg/Meter".

For More Details about unit weight of Tubes Click Here 

For Difference between Tube and Pipe Click Here

Type of Bolts

Dear Readers,

Some of the most commonly used bolts are illustrated below: This would be very useful for all construction engineers.

Hexagonal-headed bolt

This is the most common form of a bolt and is used for general fasting purposes. The hexagonal head is chamfered at its upper end. 

To prevent rotation of the bolt while screwing the nut on or off, the bolt-head is held by another spanner. A hexagonal-headed bolt illustrated in the figure. It is used for Construction and machinery applications.

Square-Headed Bolt

This bolt is commonly used when the head is to be accommodated in a recess. This recess is made of square shape so that the bolt is prevented from turning when the nut is screwed on or off.

When a square-headed bolt is to be used with its head projection outside, it is provided with a neck of square cross-section. This prevents rotation of the bolt. This bolt is commonly used in bearings for the shaft. A square-headed bolt is shown in the figure. 

Cylindrical or Cheese-Headed Bolt

This type of bolt is used where projecting corners are unacceptable, and where the space for arranging the bolt-head is relatively limited. The rotation of the bolt is prevented by means of a pin inserted into the shank just below the head.

The projecting part of this pin fits into a corresponding groove in the adjacent piece. This bolt is commonly used in big ends of connectors, eccentrics, etc.

Cup-Headed or Round-Headed Bolt

This bolt is used when projecting is undesirable and where better appearance is required.

It is usually provided with a sung forged on the shank just below the head, as shown in the figure. To prevent rotation of the bolt. This bolt is it used in the construction of tanks, certain parts of locomotives and Wooden works.

T-Headed Bolt

This type of bolt is used for securing clamps, vices, and other accessories to the tables of machine tools.

The tables are provided with T-slots to accommodate the T-heads. The neck of this bolt is usually square in section to prevent rotation of the bolt. T-bolt is shown in the figure.

Countersunk-Headed Bolt

This form of a bolt is used where the head of the bolt must not project above the surface of the connection piece.

It may be provided with a snack or a neck to prevent rotation of the bolt.

For More Information about Grade of Bolt Click Here

For More Information about Weight of Hex Bolt & Nut Here

Difference between Pipe and Tube

Dear Readers,

From a layman’s viewpoint, Both Pipe and Tube seem to be the same as they have many similarities like both are hollow, made from metals, both can transfer fluids, etc. However, there are significant differences between pipe and tube.

The difference between pipe and tube is marginal. They differ in the way they are sized. The pipe is generally specified by the internal diameter (ID) whereas tube is specified by the outside diameter (OD), but its dimensions may be given as a combination of ID, OD and the wall thickness.

What is Pipe?

Pipe is a hollow section with round cross section. Always cylindrical or round in shape for the conveyance of products. The products include fluids, gas, pellets, powders and more.

What is Tube?

Tube in general, cylindrical. However, refers to round, square, rectangular and oval hollow sections that are used for pressure equipment, for mechanical applications, and for instrumentation systems.

Unit Weight of Hex Bolt and Nut

 A bolt contains two parts a shank and head. The cylindrical portion of the bolt is known as the shank. The shank is threaded at the tail end for a sufficient length so as to effectively engage with a nut.

The shape of the head is depended upon the purpose for which bolt is required. The nut is a type of a fastener which has a threaded hole in it. The nut is always used in joining with a mating bolt to fasten various parts together.

Bolts and nuts can be made of various materials such as steel, titanium or plastic. The finish or plating on a metal bolt or nut affects its look and durability. Below are some common finishes and benefits:

• Zinc - Most common, low cost, resists corrosion and rust

• Nickel - Very hard finish, higher investment, good corrosion resistance

• Chromium – Bright finish, good rust and corrosion resistance

• Chromate – Adds color, shine, superior rust resistance

• Anodizing - Aluminum, hard oxide surface, excellent corrosion resistance

Generally purchasing of fasteners are in Kilograms instead of pieces. But we could not know how many numbers available per Kg. For construction purpose, Bulk purchase is advisable. Hence below count table will be useable. Counts are based on 50Kg

For More Information about Grade of Bolts Click Here

For More Information about Torque Clique Here

TIG Welding

Tungsten Inert Gas (TIG) Welding

TIG Welding is also a slang term commonly used. Tungsten inert gas welding (TIG welding) is a gas shielded welding process and is one of the fusion welding processes. TIG welding’s proper name is Gas Tungsten Arc Welding or “GTAW". This is the name the American Welding Society and other welding organizations refer to this process on their welding procedures. TIG welding also goes by the term HeliArc welding.

When TIG welding was introduced around the 1940’s Helium gas was the primary shielding gas used in process. The term Heliarc welding was the common phrase used back in the day Most old timers and veteran welders refer to TIG welding as Heliarc welding.

Since the name includes the term “Tungsten" and tungsten is what makes TIG welding possible, it is good to know what tungsten is! Tungsten is a very hard, slightly radioactive, and brittle metal. At 3380 degrees Celsius, tungsten has the highest melting point of all pure metals in the periodic system. This means that the electrode does not melt when it emits an arc that heats and liquefies the material. In TIG welding the tungsten is made into a non-consumable electrode that is used to create the arc for TIG welding.

THIS IS HOW A TIG WELDING SYSTEM IS STRUCTURED:

(1) Mains connection

(2) Power source

(3) Hose pack

(4) Grounding cable

(5) Welding torch

(6) Ground terminal

(7) Workpiece

(8) Filler metal

(9) Shielding gas

TIG welding requires three things, heat, shielding, and filler metal. The heat is produced by electricity passing through the tungsten electrode by creating an arc to the metal. The shielding comes from a compressed gas cylinder that flows to the weld area to protect it from air. The filler metal is just a wire that is dipped by hand into the arc and melted.

TIG Welding is a manual welding process that requires the welder to use their both hands to weld. When TIG Welding one hand is used for holding the TIG torch that produces the arc and the other hand is to add the filler metal to the weld joint.

Shielding gas is selected according to the material being welded. Argon - the most commonly-used shielding gas. Helium and helium/argon mixtures - adding helium to argon will raise the temperature of the arc. This promotes higher welding speeds and deeper weld penetration.

In the TIG welding process the arc is formed between a pointed tungsten electrode and the workpiece in an inert atmosphere of argon or helium. TIG welding must be operated with a drooping, constant current power source - either DC or AC.

ADVANTAGES OF TIG WELDING

No formation of welding spatter

Particularly high optical quality of weld seams

All welding positions are possible

Very high weld seam quality

DISADVANTAGES OF TIG WELDING

Requires high degree of skill

Low welding speeds

Rust must be removed without fail when preparing the weld seam

Not suitable for thick workpieces

Dry film thickness

Dear Readers,

Over the past several decades, industrial painting has changed, owing to the use of new, more durable finishes. Coating is the most critical component in an anticorrosive coating system. The main function of coating is to provide corrosion protection by adhesion to the substrate. A coating thickness gauge (also referred to as a paint meter) is used to measure dry film thickness.

Dry film thickness (DFT) is the thickness of a coating as measured above the substrate. This can consist of a single layer or multiple layers. DFT is measured for cured coatings (after the coating dries). Thickness of a coating depends on the application and type of process employed. DFT is a parameter that is considered during quality control or inspection processes.

Dry film thickness (DFT) can be measured using two methods: destructive thickness measurement, where the coating is cut to the substrate using a cutter; and non-destructive coating thickness measurement, using techniques which do not damage the coating

Dry film thickness can be measured on either magnetic steel surfaces or non-magnetic metal surfaces such as stainless steel or aluminium using a digital coating thickness gauge. The principle of electromagnetic induction is used for non-magnetic coatings on magnetic substrates such as steel. The eddy current principle is used for non-conductive coatings on non-ferrous metals substrates.

Types of DFT gauges include:

Magnetic pull-off (Type I)

Constant pressure probe (Type II)

Electronic magnetic flux

Eddy current gauge

Standards concerning DFT measurements include:

ISO 2808

BS 3900 Part C5

BS 5494

ASTM D1005

D1400

D2691

SIS 184160

Hot Weather Concreting

The intention of this article is to provide knowledge to general users with simple actionable works. To understand requirements, without going in to details of theoretical concepts, scientific and engineering analysis.

Concreting continuous throughout the year in construction industry but doing concreting in any extreme weather is a biggest challenge. Doing concreting in cold weather we don’t have much problem since concrete hardening being an exothermic reaction during cold weather.

To protect concrete from heat, common understanding of using chilled water is there or alternate is to do concreting in night shift. But with higher temperature in most part of the day, such strategy does not work for a durable concrete. General understanding in which concrete evaporates more than 1Kg/Sqm/Hr water.  It is perfect time to have a deep look in understanding hot weather concreting during summer.

Care during Designing

Care during Concrete Production

Care during Transportation

Care during Pouring

Care during Finishing surface and

Care during Curing

Care During Designing

Summer Concrete Shall be deigned with low heat of hydration materials.

PPC or Slag Cement, Low heat cement will help in many ways to have a good concrete with lower rate of reaction

Good quality Admixtures especially Polycarboxylic ether (PC) based can help to maintain good workability for relatively longer time and can also slowdown evaporation of water from concrete

Concrete shall be designed for the atmosphere in which the concreting is going to happen. (Maximum permissible fresh Pour Concrete is 35 Degree)

Care during Concrete Production

Care shall be taken to keep the fresh concrete temperature as lower as feasible. It is easier to care for fresh concrete rather than placed concrete

Mixing system shall not induce more heat and preferably insulation of mixing system shall be done

Cement (Bags) shall be stored in shaded area for sufficient time

Coarse aggregates shall be sprinkled with cold water

For Fine aggregates sprinkling of water if done shall be stopped couple of hour early to reduce moisture variation

For Higher temperature reduction, ice flakes shall be used

If ice flakes used shall be mixed with weighment to maintain the water cement ratio in line with design mix

Use of Liquid nitrogen is an option (Not Cost Effective and not feasible due to practical reasons)

Care during Transportation

Transportation time shall be kept minimum as much as possible (Batching location should be very nearer)

Transit Mixer drum shall be insulated to reduce the heat gain during transportation

Hessian cloth shall be used as an insulation material

Care during Pouring

During Pouring of concrete, pump pipe lines should be insulated to reduce temperature gain.

Dense Hessian cloth with sponge layer wrapping followed with wetting chilled water shall be done

Temporary shed shall be used for direct exposure to sun and wind. If shed is not feasible at least covering with thick plastic sheet shall be covered for shuttering and reinforcement before and during the concreting

Concrete pour area shall be water sprinkled (If Feasible) to cool shuttering and reinforcement. Care shall be taken that there is no standing water anywhere.

Care during Finishing surface

Late finishing shall be done before concrete starts being in semi plastic state

Evaporation reducing admixtures shall be used

Fogging of Concrete surface can be done during concrete green stage

Care during Curing. (Post Initial Set, Hardening of Concrete)

Once concrete can take a person’s weight, it is understood that concrete has initial set

Mist sprinkling of water can be done with a cover of hessian cloth

Water curing can continue either by ponding or intermittent watering surface

Time of form removal and start of curing is an important factor. Curing shall start with in 45 minutes of form removal

In short, Mass concreting during summer requires a detailed analysis, review and action plans for concrete care.

Tips for Conserve Water

Dear Readers,

We are entering the Summer, already water crises are started in major cities. So, we should start saving the water we have and use the water we have, economically. Here are a few ideas on how to conserve water.

1. Almost all of us have reverse osmosis (RO) system installed at home for water for drinking and cooking. I am sure everyone knows that it lets out almost one litre water to produce one litre drinking water. So, keep a bucket to the outlet and store this water. This can very well be used for cleaning the floor, for toilet etc. What they normally say is, the bacteria which is there in this water will die in half an hour time when get exposed to normal air.
2. Similarly, a bucket can be placed in the AC outlet. Everyday morning this water can be used for the plants in your flat, to clean your cars or even be drained into the rainwater harvesting system so that the ground water can get charged. In fact, these outlets can be connected on a regular basis to get drained there.
3. Stop using running water for cleaning utensils and use water from bucket. By this practice lot of water can be saved.
4. Similarly use shower for bathing. This also would reduce water consumption.
5. Use your washing machine when you have a full load because washing machines are designed in such a way that it uses almost the same amount of water for washing low load to very high load.
6. If your washing machine's outlet is not connected to the closed drain. That is if the machine's outlet is let out in the bathroom, then the soap water which comes out of the machine can very well be used to soak your utensils which you have used for cooking.
7. 
   Some of us face a problem with dust in the water. For example, the borewell water may turn slightly muddy when the water bed goes down or because of the accumulated dirt in the overhead tank, the water may come with dust. Please don't waste this water. Keep a block of Alum in the bathroom. Just dip this in the bucket that has the muddy water and allow it to dissolve by rotating your hand. A few rotations will do. After about 10-15 minutes you will see the dust and muddy substances settled in the bottom and crystal-clear water in the top! This Alum would be available in all medical shops.

Co2 Blasting

Dear Readers,

Co2 Blasting is the new development is quickly expanding around the world. One system uses small rice pellets of dry ice shooting them out of the jet nozzle with compressed air.

It is known by several names like dry ice cleaning, Dry Ice blasting and dry ice dusting. It is a kind of carbon di oxide cleaning, where dry ice in the solid form of carbon di oxide, is accelerated in a pressurised stream and directed in the surface in order to clean it. This method is similar to other forms of abrasive blasting such as sandblasting, or soda blasting substituted for dry ice as a blasting medium.

This method is superior to sandblasting or Short blasting because the dry ice is soft enough not to pit or damage the underlying surface. Since the dry ice evaporates completely as a gas it leaves no wastes. Only the material being removed must be disposed of.

Dry ice blasting is the superior alternative to sand blasting, short blasting, soda blasting, water blasting and hand cleaning.

Advantages of Co2 blasting:

·       No preparation required prior to cleaning

·      No need to dismantle machines for cleaning. The pellets easily reach into the smallest nooks and corners.

·       Minimal machine downtimes

·       Environmentally friendly cleaning

·       Without additional chemicals or spray agents

·       Surface are not damaged

·       No residues

Unit Weight of RSJ Pole

Dear Readers,

RSJ poles are similar to steel beams with limited sizes. It is produced by Hot rolled method. It is used in electric transmission lines, power sub stations and base frames. RSJ means Rolled Steel Joist.

It is having four sizes 100 x 116mm / 175 x 85mm / 152 x 152mm / 125 x 70. It is further classified in STD, MED, LIGHT (Standard, Medium & Light). Unit weight of RSJ poles is as follows.

For More Details of Beam Summary click Here

For More Details of Rolled Steel Section click IS808

New Year Wishes - 2020

Dear Readers,

Wish You a Happy New Year

Thousands of candles can be lighted from a single candle, and the life of the candle will not be shortened. Happiness never decreases by being shared.

Your work is going to fill a large part of your life, and the only way to be truly satisfied is to do what you believe is great work. And the only way to do great work is to love what you do. If you haven't found it yet, keep looking. Don't settle. As with all matters of the heart, you'll know when you find it

Best Wishes From

Crane & CraneMan