ITI/NCVT Sheet Metal Worker (AITT Theory) case studies
ITI/NCVT Sheet Metal Worker (AITT Theory) · Put your knowledge to work in context.
The ITI/NCVT Sheet Metal Worker trade theory paper is the written All India Trade Test (AITT) that apprentices and institutional trainees in the Sheet Metal Worker trade sit at the end of their training. It tests whether you can think like a fabricator: read a drawing, develop a true-length pattern, choose a joint, set a machine, and work safely. The ITI/NCVT Sheet Metal Worker (AITT Theory) case studies are 5 cases and about 4,563 words.
1Unaccounted Fume, a Missing Guard and a Monday Fever
At a fabrication shed, a worker shears 1.2 mm galvanised iron sheet on a treadle shearing machine whose fixed guard was taken off last week "to see the cut line better". The same worker welds the corners of GI boxes with MMA at about 90 A in a corner of the shed, while a pedestal fan blows across the bench to keep him cool.
889 words, about 4 min2Concentric Reducer Laid Out by the Wrong Method
A ductwork job needs four concentric reducers connecting 400 mm diameter round duct to 250 mm diameter round duct over a height of 300 mm. They are made from 1.6 mm galvanised sheet with a 10 mm lap seam along the slant side.
986 words, about 5 min3Rolling a 600 mm Shell on a Slip Roll
A workshop must roll a 1200 mm long shell from 3 mm mild steel plate with a 600 mm inside diameter, on a three-roll slip roll rated at 1300 mm × 3.5 mm. The operator cuts the blank using the outside diameter and rolls it with the roll gap set equal to the plate thickness, passing the sheet once in each direction at high pressure.
901 words, about 5 min4Quoting 60 GI Trays Against a Cheaper Competitor
A small shop receives an order for 60 open-top rectangular galvanised iron trays, 300 × 200 × 80 mm deep, from 1.0 mm sheet, with corners welded and a 10 mm folded edge on all sides. GI sheet costs ₹68 per kg, density is 7.85 g/cm³, and sheet is bought only in 8 ft × 4 ft sizes (2438 × 1219 mm).
828 words, about 4 min5Joining 12 m of GI Gutter on a Rainy Site
A site needs 12 m of 0.8 mm GI rainwater gutter made from four 3 m pressed sections joined end to end, fixed to a south-facing wall where the surface temperature swings by about 40 K between winter and summer. Three joining options are offered: (i) 40 mm lap soldered joint with 60/40 tin–lead solder and a liquid flux; (ii) 4 mm pop rivets at 40 mm pitch with silicone sealant; (iii) spot welding.
959 words, about 5 min