This document discusses different types of steel sections used in metal fabrication including angle irons, I-beams, round bars, flat bars, square bars, and tubes. It explains how to identify these sections and their common uses. The document also demonstrates how to calculate the back mark measurement, which is the distance from the heel of an angle or channel section to the center of a hole in the flange. Trainees practice identifying steel sections in an example and calculating back marks for angle irons of different sizes.

1. Reagan Kaihiva
Trade: Metal fabrication
Level:2
219103682
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Demonstrate knowledge of steel
section and standards

2. 1. Introduction
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What do you about
steel section ?

3. 2. Lesson objective
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By the end of this lesson trainees must able :
✓ Identify different steel sections and their uses
✓ Explain and calculate back mark standards of an angle iron

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Rolled Angle Sections Rolled Channel Sections
3. Deliberation
3.1 Different steel sections

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RolledT- Sections Rolled I – Sections
Continue..

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Rolled Round Bars Ribbed bars
Continue..

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Rolled flat bars Rolled steel plates
Continue..

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Rolled Square Bars Expanded metal
Continue..

9. Tubes
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Continue..

10. 3.2 Explain the back-mark and
calculate the back mark
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 A‘back mark’ is the distance from the heel of an angle
 channel section to the centre of a hole in a flange.
 L ≤75 + 6 / 2
 L≥76+12/2

11. 4. Check your progress
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1. Describe and identify the steel section below
1 2
3
1. Angle iron, their manufactured in L Shape use to fabricate roof
truss
2. I beam or section, used as columns
3. Round bars , used for concrete reinforcement

12. Check your progress 2
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2. Calculate the back mark of the following angle iron
(a) 50mm
(b) 40mm
Solution
(a) 50mm
50+6/2
=28mm
(b) 40mm
40+6/2
=23mm
Continue..

13. 6. Summary/conclusion
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 In this unit we have discussed the difference steel section,
explain and calculate back-mark.

14. 7. References
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 Grewa. (2018, June 04). CCOHS. Retrieved fromWorkplace
Housekeeping - Basic Guide:
https://www.ccohs.ca/oshanswers/hsprograms/house.html
 Deon, M. (Director). (2019). safety [Motion Picture].
 Marshal, D. (2019, 03 21). Practice good housekeeping in the
workplace. Retrieved 03 03, 2019, from safety and healthy
the official magazine of nsc congress and expo:
https://www.safetyandhealthmagazine.com/articles/9287-
practice-good-housekeeping-in-the-workplace