Welding Terms Part-9 (Q&R)

Dear Readers,

This continues from Part-8. Successful work execution heavily relies on both written and oral communication. For effective communication, understanding the acronyms and terms used in welding is essential.

Quality Assurance (QA) – The practice involves utilizing a defined set of processes for systematic monitoring and evaluation to ensure product quality.

Quality Control (QC) – The process of confirming that a product meets an established set of specifications. 

Quench – Rapidly cooling the steel to make it harder. The steel has to have enough carbon in it for it to harden.

Radiation – The light emitted during arc welding contains intense ultraviolet radiation (UVR). In the absence of a barrier, this radiation is emitted into the surrounding environment.

Radiography – The weld is x-rayed, and it will show even the minutest weld defects. (Slag inclusion, porosity, or undercut!)

Rake Angle – Slope of a shear knife from end to end.

Rated Load – The amperage and voltage the power source is designed to produce for a given specific duty cycle period. For example, 300 amps, 32 load volts, at 60 percent duty cycle.

Reaction Stress – The residual stress which could not otherwise exist if the members or parts being welded were isolated as free bodies without connection to other parts of the structure.

Reactor (arc welding) – A device used in arc welding circuits for the purpose of minimizing irregularities in the flow of welding current.

Reducing Flame – A gas flame that has a reducing effect, due to the presence of excess fuel.

Regulator – A device used to reduce cylinder pressure to a suitable torch working pressure.

Reinforcement – Weld metal, at the face or root, in excess of the metal necessary to fill the joint.

Residual Stress – Stress remaining in a structure or member, as a result of thermal and/or mechanical treatment. Stress arises in fusion welding primarily because the melted material contracts on cooling from the solidus to room temperature.

Resistance Brazing – A brazing process in which bonding is produced by the heat obtained from resistance to the flow of electric current in a circuit of which the workpiece is a part, and by using a nonferrous filler metal having a melting point above 800 ºF (427 ºC), but below that of the base metals. The filler metal is distributed in the joint by capillary attraction.

Resistance Butt Welding – A group of resistance welding processes in which the weld occurs simultaneously over the entire contact area of the parts being joined.

Resistance Spot Welding (RSW) – Uses electrical current which is passed through the metal. It does not require a filler rod. The process is easy to automate and requires low heat input.

Resistance Welding – A group of welding processes in which fusion is produced by heat obtained from resistance to the flow of electric current in a circuit of which the workpiece is a part and by the application of pressure.

Reverse Polarity – The arrangement of direct current arc welding leads with the work as the negative pole and the electrode as the positive pole of the welding arc.

Robotic Welder – A fully or partially automated machine equipped with a welding head and connected to a welding power source. The movable portion of a robotic welder is normally a robotic arm.

Rockwell Hardness Test – In this test a machine measures hardness by determining the depth of penetration of a penetrator into the specimen under certain arbitrary fixed conditions of test. The penetrator may be either a steel ball or a diamond Sphero cone.

Rods – Same as welding electrode. At site or shop, nobody asks for more "electrodes", they ask for more rods.

Root Crack – A crack at the root of a weld.

Root Edge – The edge of a part to be welded which is adjacent to the root.

Root Face – That portion of the groove face adjacent to the root of the joint.

Root of Joint – That portion of a joint to be welded where the members approach closest to each other. In cross section the root of the joint may be either a point, a line or an area.

Root of Weld – The points, as shown in cross section, at which the back of the weld intersects the base metal surfaces.

Root Opening – A separation at the joint root between the work pieces.

Root Penetration – How far the Filler Metal is penetrating into and through the Root Opening.

Root Reinforcement – Reinforcement of weld at the side other than that from which welding was done.

Root Surface – The exposed surface of a weld on the side other than that from which welding was done.

Find a Suitable Spanner

 Dear Readers,

In the construction industry, one of the most commonly used tools is the spanner. This versatile tool is mainly used for gripping and turning fasteners like nuts and bolts. Spanners are tools made to give you a good grip and extra leverage when tightening or loosening rotary fasteners. Usually crafted from carbon steel or drop-forged steel, they come in a range of shapes and sizes to suit different needs.

Metric spanners (mm) and imperial spanners (inch) are both available, but the construction industry mostly uses the metric system. Metric spanners are labeled in millimeters (mm). The nominal size (e.g., M12) refers to the thread diameter, not the spanner size.

The best way to find the right spanner size is to measure the distance across the flat sides (AF) of the nut or bolt head with a measuring tool. If you don’t have one handy, you can refer to a size chart or use a general formula for standard bolts instead.

A general formula provides a good estimate for standard hexagonal metric bolts:

For bolts up to M14: Spanner size = (Bolt diameter × 1.5) + 1 mm.

(e.g., M8: (8 × 1.5) + 1 = 13 mm).

For bolts M16 and above: Spanner size = Bolt diameter × 1.5 mm.

(e.g., M16: 16 × 1.5 = 24 mm).

Spanners are essential tools in various industries including Construction, providing the necessary grip and torque to handle fasteners effectively.

Levels of a Project Schedule

 Dear Readers,

The project's success relies on various activities, with effective scheduling being crucial. A project schedule refers to a tool used to communicate the timeline of a project, including its tasks, dependencies, assigned resources, and milestones. It serves as a roadmap for the project.

Key components of a project schedule are Project Milestones, Timeline, Tasks, Dependencies, and resources. Schedules are typically developed from the top down, like a pyramid. Starts from Level-1 (L1), Level-2 (L2), and will go up to Level-5 (L5).

L-1 Schedule = (Level 1) Management/Milestone Level Schedule 

L-2 Schedule = (Level 2) Master Schedule 

L-3 Schedule = (Level 3) Project Level Schedule 

L-4 Schedule = (Level 4) Control Level Schedule 

L-5 Schedule = (Level 5) Detail Level Schedule or Look-ahead Schedule

L1 may be a short table of milestones corresponding to "Top Management Summary." 

L2 is a Master Schedule. It provides an integral plan of the Project activities for Project management. It is a "Project Management Summary." 

L3 is a Project Level Schedule. It is a summary of activities from the level 4 schedule 

L4 is a Control Level Schedule. It covers the whole project and doesn't go into the task-level detail, but should provide enough of a breakdown for clients to see what is happening at every step.

L5 is a Detail Level Schedule. It shows the lowest level of detail necessary to complete the Task. These schedules are temporary documents based on the 'Look-ahead' schedule and used to coordinate work in an area. 

The schedules above help communicate the project plan and timeline to all stakeholders. They guide the project team through the sequence of activities and deadlines during execution, while also serving as a baseline to track progress, spot delays, and make adjustments as needed.

Common formats used to prepare and monitor the project schedules are Gantt chart, WBS & CPM

Gantt chart: A popular visual representation that uses a horizontal bar chart to show the timeline of tasks and their dependencies. 

Work Breakdown Structure (WBS): It is a hierarchical chart that breaks down a project into smaller, more manageable tasks, helping to map dependencies. 

Critical Path Method (CPM): A technique to identify the longest sequence of tasks that determines the minimum project duration. Any delay to a task on the critical path delays the entire project. 

Thank you for reading this article. I hope you found it beneficial and helpful as a beginner in the construction industry. If you found this article useful, please don't forget to share it with your friends and colleagues.