Welding Terms Part-11 (T to V)

This is a continuation of Part-10. Welding management is a highly technical field requiring specialized acronyms and abbreviations to effectively communicate and manage complex projects. Hence, we should know the terms used in welding work.

1. Tack Weld – A weld made to hold parts of a weldment in proper alignment until the final welds are made.

2. Tee Joint - Joints are formed when two pieces intersect at a 90° angle. This results in the edges coming together in the center of a plate or component in a 'T' shape.

3. Temper - Some steels can be hardened by heating, then quickly quenching. When our chipping hammers get dull, we sharpen, then temper them.

4. Temper Colors - The colors which appear on the surface of steel heated at low temperature in an oxidizing atmosphere.

5. Temper Time - In resistance welding, that part of the post-weld interval during which a current suitable for tempering or heat treatment flows. The current can be single or multiple impulses, with varying heat and cool intervals.

6. Temporary weld - A weld made to attach a piece or pieces to a weldment for temporary use in handling, shipping, or working on the weldment.

7. Tenacious – Cohesive, tough.

8. Tensile Strength – The maximum stress a material can endure under a stretching load without tearing is known as its tensile strength.

9. Tension - Pulling taut or stretching with force. A good example is a rubber band. Tension is when you stretch it apart.

10. 
    Tension Test - A test in which a specimen is broken by applying an increasing load to the two ends. During the test, the elastic properties and the ultimate tensile strength of the material are determined. After rupture, the broken specimen may be measured for elongation and reduction of area.

11. Test Coupon - A weld test coupon is a small piece of metal used to test a welder’s proficiency in various welding procedures.

12. Thermal Conductivity – The quantity of heat passing through a material.

13. Thermal Spraying – A group of processes in which finely divided metallic or non-metallic materials are deposited in a molten or semi-molten condition to form a coating.

14. Thermal Stresses – Stresses in metal resulting from non-uniform temperature distributions.

15. Thermit Crucible - The vessel in which the thermit reaction takes place.

16. Thermit Mixture - A mixture of metal oxide and finely divided aluminum with the addition of alloying metals as required.

17. Thermit Mold - A mold formed around the parts to be welded to receive the molten metal.

18. Thermit Reaction - The chemical reaction between metal oxide and aluminum which produces superheated molten metal and aluminum oxide slag.

19. 
    Thermit Welding - A group of welding processes in which fusion is produced by heating with superheated liquid metal and slag resulting from a chemical reaction between a metal oxide and aluminum, with or without the application of pressure. Filler metal, when used, is obtained from the liquid metal.

20. Thermionic – The emission of electrons as a result of heat.

21. Thermocouple - A thermoelectric device for measuring temperature which consists of two wires of two differing metals which are connected at two points, a voltage being developed between the two junctions in proportion to the temperature difference provides the capacity for measuring difference in temperature.

22. Throat – In welding, the area between the arms of a resistance welder. In a press, the distance from the slide centerline to the frame of a gap-frame press.

23. THROAT OF FILLET WELD - This term encompasses two measurements. The theoretical throat is the perpendicular distance from the root of the joint to the hypotenuse of the largest inscribable right triangle within the fillet-weld cross-section. The actual throat, on the other hand, refers to the distance from the root of the fillet weld to the center of its face. Both measurements are crucial in determining the strength and quality of the weld.

24. Tie-in - After running a STRINGER BEAD, a tie-in is made when another stringer bead parallel to the first is burned halfway into it. Instead of them being two beads side by side, they are intertwined together. Tie-in is very important to give strength when making multiple pass welds.

25. TIG (P) - Pulsed TIG - A modified TIG process appropriate for welding thinner materials.

26. Tig Torch – It is like a welding holder, made up of a head to protect the tungsten, collet body, tungsten, and a ceramic cup.

27. TIG Welding – See Gas Tungsten Arc Welding (GTAW).

28. Toe crack - A crack in the base metal occurring at the toe of a weld.

29. Toe of weld - The junction between the face of a weld and the base metal.

30. Torch - A device used in the TIG (GTAW) process to control the electrode position, transfer current to the arc, and direct the shielding gas flow.

31. 
    Torch Brazing - A brazing process in which bonding is produced by heating with a gas flame and by using a nonferrous filler metal having a melting point above 800 ºF (427 ºC), but below that of the base metal. The filler metal is distributed in the joint of capillary attraction.

32. Torch Standoff Distance – The dimension from the outer face of the torch nozzle to the workpiece.

33. Transferred Arc – In plasma arc welding, a plasma arc is established between the electrode and the workpiece.

34. Tungsten - This stuff is hard! It also has the highest melting point(3410° Celsius) of any metal, with only the element carbon having a higher one. This makes it a good Electrode to use in TIG.

35. Underbead Crack – A crack in the heat-affected zone generally not extending to the surface of the base metal.

36. Undercut – A groove melted into the base plate adjacent to the weld toe or weld root and left unfilled by weld metal.

37. Underfill – It is a weld Defect that happens when you are not depositing enough filler metal according to the welding specs.

38. 
    
    Underwater Welding - Underwater welding, also known as hyperbaric welding, involves welding at elevated pressures. The welding can either take place in the water itself (known as wet welding) or in a dry, pressurised enclosure (known as dry welding).

39. UPSET - A localized increase in volume in the region of a weld, resulting from the application of pressure.

40. Upset Welding - A resistance welding process in which fusion is produced simultaneously over the entire area of abutting surfaces, or progressively along a joint, by the heat obtained from resistance to the flow of electric current through the area of contact of those surfaces. Pressure is applied before heating is started and is maintained throughout the heating period.

41. Upsetting Force - The force exerted at the welding surfaces in flash or upset welding.

42. Vapor Pressure – The pressure exerted by a vapor when a state of equilibrium has been reached between a liquid, solid, or solution and its vapor. When the vapor pressure of a liquid exceeds that of the confining atmosphere, the liquid is commonly said to be boiling.

43. Vertical position - The welding position in which the axis of the weld is nearly vertical.

44. Viscosity – The resistance that a fluid (either a liquid or a gas) presents to flow.

45. Visual Inspection – It is the easiest and most fundamental Weld Test. After the weld is completed, a qualified inspector will examine it closely. The inspection will check for issues such as undercut, porosity, and underfill.

46. Voltage – It is the force that causes electrons to flow through a conductor.

47. Voltage regulator - An automatic electrical control device that keeps a steady voltage supply to the primary of a welding transformer.

Multitasking

Dear Readers,

Recently, I came across a humorous meme that serves as an eye-opener for completing result-oriented tasks. At first glance, the image looks impressive, as it seems to show someone multitasking effectively and saving time. However, a closer look reveals that this approach is completely impractical, resulting in zero progress despite being fully occupied. In reality, it conveys 0% progress and 100% occupation.

He can’t use his laptop because he’s holding a drink.

He can’t drink because he has a cigar in his mouth.

He can’t smoke his cigar because both hands are occupied.

This is a Masterpiece of multitasking, where absolutely nothing gets done.

…..where someone is 100% occupied but 0% productive?

In your professional life, you may reach a point where you are either an employee or a manager. The first thing you need to understand is the difference between multi-skilling and multi-tasking.

When you concentrate fully on one task at a time, you are more likely to complete it successfully and maintain high quality. In contrast, attempting to juggle multiple tasks simultaneously often results in none of them being finished well or providing a sense of fulfillment.

In conclusion, multi-skilling is more crucial than multitasking. To effectively perform multitasking, one must have a range of skills.

Bolt Grades

Dear Readers,

In construction engineering, bolts are frequently used. The grades of bolts typically range from 4.6 to 12.9. These are also referred to as Ordinary bolts (Commercial Grade), HT bolts (High Tension), and HSFG bolts (High Strength Friction Grip).

The bolt designation system consists of two numbers. The first number indicates the bolt's ultimate tensile strength, which can be 400 MPa, 800 MPa, or 1200 MPa. The second number signifies the point at which the bolt will permanently stretch. Specifically, a grade 4.6 bolt will permanently stretch at 60% of its ultimate tensile strength, a grade 8.8 bolt at 80%, and a grade 12.9 bolt at 90%.

Technically, it can be quoted that the first number is the tensile strength of the bolt material (N² )/100. The second number is = 1/100. (the ratio of the Proof (or Yield ) stress and the Tensile strength expressed as a percentage = 100.[Yield (Proof stress) /Tensile strength] /100

For example, the tensile and proof strength of the steel for an 8.8 bolt is therefore calculated as follows

Tensile strength = 8 X 100 N/mm² = 800 N/mm² and Proof strength = 0.8*800 * 100 /100 = 640 N/mm² (generally speaking 80% of 800N/mm2)

The lowest grade is 4.6, commonly known as commercial grade. Next comes grade 8.8, known as structural grade, and finally, the highest grade is 12.9, known as HT / HSFG bolt.

Available grades of bolts are 4.6, 4.8, 5.6, 5.8, 6.8, 8.8, 9.8, 10.9 & 12.9

Cost of Man Day

 Dear Readers,

Let us discuss how to calculate the Man Day cost. MD refers Man Day; it is a unit of measurement for workforce.

Eight-Hour working is called One shift and one person working one shift (8 Hours) is called one man day. 

If the work gang comprises 10 workmen and working one shift is equal to 10 MD and if the gang works 6 days then it is 60MD.

In construction industry over time has existed. It is subject to the nature of job. Normally 3 Hours overtime is regular in all sites. However, benefits will not be applicable on overtime wages.

During MD rate calculations terminal benefits are subject to the duration and local site environment

MD rate arrives from

             ABW (Average Basic Wages)

             Over Time Wages 

             PF & Admin. Charges of employer portion

             Terminal benefits 

There are several laws in India which govern the maximum overtime hours allowed in India and also provide for an overtime calculation formula in India. Based on the industry one works for; the overtime payment rules vary. Some workplaces may be governed by the central laws while the other might be a subject of state laws.

Welding Terms Part-10 (S)

Dear Readers,

This continues Part-9. Knowing the list of welding abbreviations is crucial. Recognizing these abbreviations is the initial step in blueprint reading. Therefore, understanding the terms used in welding is essential.

Scarf – The chamfered surface of a joint.

Scarfing – A process for removing defects and checks which develop in the rolling of steel billets by the use of a low velocity oxygen de-seaming torch.

Scarf Joint – A form of butt joint.

Scratch Start TIG – A common method of striking an arc in the TIG welding process which involves dragging the tungsten electrode across the surface of the metal.

Seal Weld – Any weld designed primarily to provide a specific degree of tightness against leakage.

Seam Weld – The seam is right where the two plates, strips, etc. touch. It is important that you get half of the Weld Pool on each side of the seam.

Semi-Automatic Welding – MIG is an example. The machine runs the wire (Filler Metal) and supplies the Shielding Gas automatically, but it takes a person to pull the trigger and manipulate the gun to make the weld.

Self-Shielded Flux Cored Arc Welding (FCAW-S) – A flux-cored arc welding process variation in which shielding gas is obtained exclusively from the flux within the electrode.

Series Welding – A resistance welding process in which two or more welds are made simultaneously by a single welding transformer with the total current passing through each weld.

Sheet Separation – In spot, seam, and projection welding, the gap surrounding the weld between faying surfaces, after the joint has been welded.

Shielded Metal Arc Welding (SMAW) – A process that welds by heat from an electric arc, between a flux-covered metal electrode and the work. Shielding comes from the decomposition of the electrode covering.

Shielding Gas – Protective gas used to prevent atmospheric contamination.

Shoulder – The portion of the prepared edge of a member to be joined by a groove weld which is not beveled or grooved.

Shrinkage Stress – Stress remaining in a structure or member as a result of thermal and/or mechanical treatment.

Shrinkage Void – A cavity-type discontinuity normally formed by shrinkage during solidification.

Single Impulse Welding – The making of spot, projection, and upset welds by a single impulse of current. When alternating current is used, an impulse may consist of a fraction of a cycle or a number of cycles.

Single-Welded Joint – In arc and gas welding, any joint welded from one side only.

Size of Weld – The size of weld refers to the dimensions of the weld, typically its diameter or width and depth, depending on the type of weld.

Skip Weld – A sequence used to control warping (distortion).

Skull – The un-melted residue from a liquated filler metal.

Slag – when the Flux on a welding Rod melts it produces the Shielding Gas to protect the weld, and then forms a hardened protective coating over the weld. It is called Slag.

Slag Inclusion – Slag inclusions are one of the main Weld Defects. If you don't properly clean the Slag from a Bead, you run the risk of it becoming part of the weld when you run the next bead.

Slot – Slot welds are just like Plug Welds except instead of being round, they are elongated. (Long and narrow/ Elongated Hole).

Slugging – The act of adding a separate piece or pieces of material in a joint before or during welding that results in a welded joint not complying with design, drawing, or specification requirements.

SMAW – Shielded Metal (stick) arc welding uses a consumable electrode that has a solid metal rod in the core. The rod and electrode melt down and become part of the weld. The electrode is flux coated to protect the weld from contamination.

Soldering – A joining process using a filler metal with a liquidus less than 840 °F and below the solidus of the base metal.

Solid State Welding – A group of welding processes which produces coalescence at temperatures essentially below the melting point of the base materials being joined, without the addition of a brazing filler metal. Pressure may or may not be used.

Solidus – The highest temperature at which a metal or alloy is completely solid.

Spacer strip – A metal strip or bar prepared for a groove weld and inserted in the root of a joint to serve as a backing and to maintain root opening during welding. It can also bridge an exceptionally wide gap due to poor fit up.

SPALL – Small chips or fragments which are sometimes given off by electrodes during the welding operation. This problem is especially common with heavy-coated electrodes.

Spatter – Metal particles expelled during welding that do not form a part of the weld.

Spatter loss – Metal lost due to spatter.

Spot Weld – (also known as resistance spot welding) is a resistance welding process. This welding process is used primarily for welding two or more metal sheets together by applying pressure and heat from an electric current to the weld area. Used on thin gauge metal like car bodies.

Spray Transfer – In arc welding, a type of metal transfer in which molten filler metal is propelled axially across the arc in small droplets.

Spray Welding – Another term for spray arc welding or GMAW.

Square-Groove Weld – A type of groove weld.

Staggered Intermittent Fillet Welding - Two lines of intermittent fillet welding on a joint in which the fillet weld increments are one line are staggered with respect to those in the other line.

Standard Temperature and Pressure (STP) – An internationally accepted reference base where standard temperature is 0 °C (32 °f) and standard pressure is one atmosphere, or 14.6960 psia.

Steel – Steel is iron ore mined from the ground, purified in blast furnaces, and then carbon added in its molten stage.

Stick Welding – Same as Shielded Metal Arc Welding (SMAW)

Sticking – It is the occurrence when the rod sticks to the steel instead of starting an arc. It's usually caused by the heat not being hot enough, or the wrong ROD angle.

Stick-Out – The length of nonmelted electrode extending beyond the end of the contact tube in continuous welding processes.

Stitch Welding – The use of intermittent welds to join two or more parts.

Stinger – Another name for the SMAW electrode holder.

Stored Energy Welding – The making of a weld with electrical energy accumulated electrostatically, electromagnetically, or electrochemically at a relatively low rate and made available at the required welding rate.

Straight Polarity – Direct current arc welding where the work is the positive pole.

Stress Corrosion Cracking – Failure of metals by cracking under combined action of corrosion and stress, residual or applied. In brazing, the term applies to the cracking of stressed base metal due to the presence of a liquid filler metal.

Stress Relief Heat Treatment – Uniform heating of a welded component to a temperature sufficient to relieve a major portion of the residual stresses.

Stress Relief Cracking – Cracking in the weld metal or heat affected zone during post-weld heat treatment or high temperature service.

Stringer Bead – A weld bead made without transverse movement of the welding arc.

Stud Welding – A process for attaching a fastener, bolt or nut to a metal base. Fasteners attached during the stud welding process are usually threaded, unthreaded or tapped variety.

Submerged Arc Welding – A process that welds with the heat produced by an electric arc between a bare metal electrode and the work. A blanket of granular fusible flux shields the arc.

Substrate – Any material upon which a thermal-spray deposit is applied.

Surfacing – Welds used to build up worn down equipment to its original form. A good example is a bulldozer bucket tooth.

Synergistic – An action where the total effect of two active components in a mixture is greater than the sum of their individual effects.

Code of Engine Oil

Dear Readers,

As you are aware, water is important to humans and their livelihoods; similarly, Engine oil is essential for an engine. Not only does it lubricate engine components, but it also cleans them and protects them from corrosion.

When purchasing engine oil, you will see numbers like 15W-40, 20W-40, and 5W-30 printed on the containers. This information is crucial for both two-wheeler and four-wheeler owners and drivers. Engine oil usage depends on vehicle operation and weather conditions, such as daytime or nighttime, summer (hot) or winter (cold), and flat or mountainous roads.

Therefore, the specifications of the oil are based on research findings related to these factors. This is why the engine and driving conditions are two crucial factors in determining the right engine oil for your car. Individual oil products are labeled with a range of temperatures indicated in degrees Celsius to specify their suitability for vehicle operation. For instance, oil marked as 15W-40 is ideal for vehicles operating in hot weather. Conversely, in colder climates, using oil with a rating of 5W-30 would lead to better engine performance.

SAE (Society of Automotive Engineers) is a global standards organization that grades engine oils based on their viscosities for classification..

The engine oil grade is represented by an alphanumeric code, commonly formatted as XW-XX. Let us clarify what each character signifies.

The "W" stands for WINTER, and the number before the "W" indicates the oil's viscosity at low temperatures, or when the engine is cold. Generally, a lower viscosity means better pumping and flow capabilities in colder temperatures. The number following the hyphen (-) indicates the oil's viscosity at normal operating temperatures, which is approximately 100 degrees Celsius in an engine.

For example, 10W-30. The 'W' indicates winter, while the number 10 signifies the oil's thickness at lower temperatures or before starting the engine.

The lower the viscosity of an oil, the better it can be pumped and flow in cold temperatures. Therefore, in extremely cold conditions and during engine start-up, 0W oil flows more quickly than 5W oil, allowing it to reach crucial engine components such as pistons, valves, and cylinder walls more efficiently.

Whereas the number 30 after the hyphen indicates the oil thickness at normal engine running temperature.

Consider using oils with higher viscosity ratings (like 40 or 50) for better protection against high temperatures.

Next time you need to change your engine oil or are thinking about purchasing oil, make sure to check your vehicle's owner's manual for the recommended oil grade. I hope this article has been helpful to you. Having a basic understanding of this process can instill a sense of confidence.

SWL

Dear Readers,

On a construction site, you may often notice SWL warning messages on lifting tools and tackle. SWL stands for Safe Working Load. Understanding key terms like Safe Working Load (SWL) and Working Load Limit (WLL) is important for ensuring safety, efficiency, and adherence to best practices in material handling.

SWL is very important and essential for rigging & hoisting works during construction activities, and sometimes stated as the Normal Working Load (NWL). 

It’s the mass or force that lifting equipment, a device, or an accessory can safely handle to lift, hold, or lower a load without the risk of breaking. This is usually marked on the equipment by the manufacturer and is often set at 1/5 of the Minimum Breaking Strength (MBS), though other fractions like 1/4, 1/6, or 1/10 may also be used.

The SWL is determined by dividing the minimum breaking strength (MBS) of a component by a safety factor assigned to that type and use of equipment. The safety factor generally ranges from 4 to 6 unless a failure of the equipment could pose a risk to life; in that instance, the safety factor would be 10.

For example, if a line has an MBS of 1,000 pounds and a safety factor of 5, then the SWL would be 200 pounds. 1000/5 = 200.  

Thumb Rule for Determination of SWL of Wire Rope Slings:

SWL = 8*D2; in Tons; Where D diameter of the rope in inches.

Example: 

    1 Inch diameter rope 1*1*8 = 8 Tons 

    ½ inch diameter rope 0.5*0.5*8 = 2 Tons

Another way to calculate the SWL of any wire rope is by 

    1. Obtained the Breaking strength of the wire rope as per the class.

    2. Consider the Safety factor (Generally taken as 5 for wire rope, except taken as 10 when used for lifting a person)

    3. Divided the breaking Strength by the factor of safety.

Whether you’re an experienced engineer, a safety officer, or just starting out in the industry, understanding these concepts can make a big difference in creating a safer workplace.

New Year Wishes

Dear Readers,

Wish You a Happy New Year - 2026

Happy New Year just feels good to say. Doesn’t matter where you’re from, your religion, your country—everybody celebrates it.

Happy new year, happy new year. May we all have a vision now and then of a world where every neighbor is a friend.

Regards,

S. Arivazhagan & Arivu