A drilled hole goes out of centre due to
Improper clamping of workpiece
Workpiece having blowholes
Centre punch mark not being large enough to give proper seat to the chisel edge of drill
A drilled hole goes out of centre due to
Improper clamping of workpiece
Workpiece having blowholes
Centre punch mark not being large enough to give proper seat to the chisel edge of drill
The grade of file tool is listed below
1. Rough
2. Bastard
3. Second Cut
4. Smooth
5. Dead Smooth
1) Rough File : A rough file is used for removing rapidly a larger quantity of metal. It is mostly used for trimming the rough edges of soft metal castings.
2) Bastard File: A bastard file is used in cases where there is a heavy reduction of material.
3) Second Cut File: A second cut file is used to give a good finish on metals. It is excellent to file hard metals. It is useful for bringing the jobs close to the finishing size.
4) Somooth File: A smooth file is used to remove small quantity of material and to give a good finish.
5) Dead Smooth File: A dead smooth file is used to bring the material to accurate size with a high degree of finish.
The rasp cut has individual, sharp, pointed teeth in a line, and is useful for filing wood, leather and other soft materials. These files are available only in half round shape.
A half round scraper is the most suitable scraper for scraping curved surfaces. This method of scrapping differs from that of flat scraping.