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Showing posts from March, 2015

Lathe Operations: Facing

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Facing Operations Facing is the process of removing metal from the end of a workpiece to produce a flat surface. Most often, the workpiece is cylindrical, but using a 4-jaw chuck you can face rectangular or odd-shaped work to form cubes and other non-cylindrical shapes.

When a lathe cutting tool removes metal it applies considerable tangential (i.e. lateral or sideways) force to the workpiece. To safely perform a facing operation the end of the workpiece must be positioned close to the jaws of the chuck. The workpiece should not extend more than 2-3 times its diameter from the chuck jaws unless a steady rest is used to support the free end. Cutting Speeds

If you read many books on machining you will find a lot of information about the correct cutting speed for the movement of the cutting tool in relation to the workpiece. You must consider the rotational speed of the workpiece and the movement of the tool relative to the workpiece. Basically, the softer the metal the faster the cutting. D…

Basics of Arc Welding

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Introduction to Metals
[wptab name='Source and Manufacturing']
Source and Manufacturing
Metals come from natural deposits of ore in the earth’s crust.  Most ores are contaminated with impurities that must be removed by mechanical and chemical means.  Metal extracted from the purified ore is known as primary or virgin metal, and metal that comes from scrap is called secondary metal.  Most mining of metal bearing ores is done by either open pit or underground methods.  The two methods of mining employed are known as “selective” in which small veins or beds of high grade ore are worked, and “bulk” in which large quantities of low grade ore are mined to extract a high grade portion.
There are two types of ores, ferrous and nonferrous.  The term ferrous comes from the Latin word “ferrum” meaning iron, and a ferrous metal is one that has high iron content.  Nonferrous metals, such as copper and aluminum, are those that contain little or no iron.  There is approximately 20 times the tonn…

How to Join Two Tables and Print Data From Both Tables in Single Table in SQL?

I was given a task to fetch data from multiple tables and bring them to a single table so that it can be used for wider requirement. Let me give some background of the data source and the structure of data so that you can give a correct solution to it.
My office has a very wider database which is consisting of more than 200 tables in it. So, there is one primary key which is called "Code" the field name which is common in all the tables and rest all data are uncommon in all the tables.
For example:
Table 1 contains field names  "code, name, supplier, location,"
Table 2 contains field names "code, country, price, Weight, language"
Table 3 contains field names "code, mfd, expiry, batch, received"
Now I am tasked to print the fields in single table like "code, name, mfd, expiry, location, weight, price"
I have tried to do it by the "join" command but there I am unable to do it with that function. There I am able to fetch data from two …

Types of Drives in Slotting Machine

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These machines utilize three types of drives. These are rack driven, screw driven, and crank driven. The crank driven being most common because of the variety of work, which they undertake, normally.

Main Parts of Slotting Machine
The various main parts of slotting machine are as mentioned below:


Frame or Column. This is a massive casting of great strength designed to carry all the working part of the machine.
Table. Table of slotter holds the work piece and is adjustable in longitudinal and cross-wise directions. The table can be rotated about its centre. Hand wheels are provided for longitudinal, cross and rotary movements of the table.

Note: The transverse and longitudinal movements are at 90° to each other.


Carriage. This carries the table to which it is mounted and provides means for transverse movement of the table.
Saddle. This is mounted on the carriage, which carries the table and provides means for longitudinal movement of the table towards or away from the column.
Bed Ways.  These …

Types of Slotters Used in Slotting Machine

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Various types of slotters are designed to suit various requirements. There are three types of slotters.
(a) Puncher Slotter.The puncher slotter is a heavy, rigid machine designed for removal of large amount of metal from large forgings or castings. The length of stroke of a puncher slotter is sufficiently large. It can remove 1.5 Kg to 2.5 Kg of material in one minute. Locomotive crank webs can be slotted from the rectangular shapes to exact size in less time than by any other method.
(b) General Production Slotter. This is widely used for general purpose production work. This may be divided into two classes. These are as follows:
(i) Those having solid body construction
(ii) Those having arrangements to tilt the body of the machine about 10° forward and backward for machining accurate internal and external tapers.
(c) Precision Tool Room Slotter. A considerable amount of tool room work is carried out on standard production slotter but the value of a precision slotter for this class of wor…

Purpose, Importance and Functions of Slotting Machine

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A Slotting machine may also be known as heavy-duty shaper. Slotting machine resembles a shaping machine in all respect except that the ram instead of reciprocating to and fro in the horizontal plane, moves up and down in the vertical plane. Therefore, the slotting machine is some times called as vertical shaper.


Purpose of Slotting Machine
It is very useful for making keyways, machining square holes, cutting of internal and external teeth on big gears, machining of dies, punches, etc. The job is generally supported on a round table, which has rotary feed in addition to the usual table movement in cross direction.

Importance of Slotting Machine
It is very useful for making keyways, machining square holes, cutting of internal and external teeth on big gears, machining of dies, punches, etc. The job is generally supported on a round table, which has rotary movement in addition to the usual table movement in cross direction. The stroke of slotting machine ranges from 8” to 12”.  Slotter does …