Page 217 - CITS - Fitter Trade Practical - Volume -2

FITTER - CITS

• Apply prussion blue evenly on the surface plate.
• Place the job on surface plate and move slightly forward and backward
• Take the job from surface plate and notice the blue spotted marks on the flat surface.
• Hold the job in bench vice

• Scrap and remove the high spots on the flat surface of the job using flat scraper Fig 1.
• Wipe off the scraped surface with soft cloth to remove burrs.
• Again, place the scraped surface on prussion blue applied surface and move forward and backward and notice
the high spot marks.

Fig 1

• Repeat the scraping process untill the prussion blue spotted marks spread over the entire surface of the job.
• Wipe off the scraped surface with soft cloth.
• Apply thin coat of oil and pressure it for evaluation.

TASK 2: Scraping on curved surface
• Check the raw material for its size.
• File metal to size 90x48x18 mm maintaining flatness and squareness.

• Check the size with vernier caliper.
• Apply marking media, mark and punch as shown in Fig 1.

Fig 1

• Chain drill holes remove excess material as shown in Fig 2.

• Cut and remove the hatched portion of chain drilled holes excess metal using web chisel and ball pei hammer
as shown in Fig 3.
• File curved surface with half round file and check the curved profile with template.

• Hold the round test bar Ø 60 mm in bench vice along with aluminium vice clamps.
• Apply thin coat of prussion blue on the one end of cylindrical surface of test bar.

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CITS : C G & M - Fitter - Exercise 91