This document provides a lesson on files used in mechanical engineering. It defines files and their parts, different shapes of files, types of files including hand and flat files, methods of filing like cross, draw and profile filing, filing terms including cut and grade, and care of files. The objectives are to be able to identify parts of files, shapes, filing methods, terms, and use files properly to shape metal.

1. Mechanical Engineering
Technology.
Lesson Topic: Files.
Objectives
At the end of the lesson students should be able to:
1.State the uses of files.
2.Identify the parts of files
3.Identify various shapes of files
4.State and define three methods of filing.
5.State how to care for files
6.Explain some terms used in filing.
7.Use the file to shape metal.
WELCOME

2. FILES
FILES ARE COMMONLY USED
IN MECHANICAL
ENGINEERING TECHNOLOGY
FOR SHAPING WORK.
THEY ARE MADE OF HIGH
CARBON STEEL WHICH IS
HARDENED AND TEMPERED.
FILES ARE MADE IN VARIOUS
SIZES AND SHAPES.

3. Parts of the file
. length
tip shoulder
tang
ferrule handleteeth

4. Shape of files
CROSS SECTIONS
flat Half roundround
knifetriangularsquare
hand

5. TYPES OF FILES
THE HAND FILE IS ALSO CALLED THE
SAFE EDGE FILE.IT IS PARALLEL
THROUGHOUT ITS LENGTH, HAS ONE
EDGE (SAFE) WITHOUT TEETH AND
IS USED FOR GENERAL PURPOSES.
THE FLAT FILE IS PARALLEL FOR
TWO THIRD OF ITS LENGTH AND HAS
TEETH ON ALL FOUR SIDES. IT IS
USED FOR GENERAL PURPOSES.

6. Care of files.
Never use a file without a handle
Clean the teeth as soon as they
become pinned.
Keep files in a dry place.
Never use the file as a hammer.
Never allow the file to slip over the
work when filing.
Never use a small file when a large
one can do the work better.

7. Filing Terms.
There are two common
terms used in filing;
The cut of the file.
The grade of the file.

8. The cut of the file
The cut of the file indicates the
particular way in which the teeth
are cut. They may be single cut,
double cut or rasp cut.
single double rasp

9. THE GRADE OF THE
FILE.
THIS INDICATES THE DEGREE
OF COARSENESS OF THE
TEETH.
THE GRADES BEING; ROUGH,
BASTARD, SMOOTH OR DEAD
SMOOTH.

10. METHODS OF FILING
CROSS FILING
DRAW FILING
PROFILING

11. CROSS FILING
THIS METHOD IS USED
FOR ROUGHING DOWN.
THIS IS DONE BY
HOLDING THE FILE AT THE
TIP AND AT THE HANDLE,
PUSHING IT ACROSS THE
SURFACE OF THE WORK.

12. DRAW FILING
THIS METHOD IS USED WHEN
FINISHING A SURFACE AND
IS USUALLY DONE AFTER
CROSS FILING.
THE FILE IS HELD AT RIGHT
ANGLE TO THE WORK AND AS
CLOSE TOGETHER AS
POSSIBLE THEN PUSHED
BACK AND FORTH.

13. PRO FILING
THIS METHOD IS
USED TO PRODUCE
CURVES ON WORK.
THE CURVES MAY BE
CONVEX OR
CONCAVE.

14. CONCAVE FILING
IN CONCAVE FILING THE
FILE IS TWISTED AND
PUSHED FORWARD. A
ROUND OR HALF ROUND
FILE MAY BE USED.

15. CONVEX FILING
IN CONVEX FILING THE TIP
OF THE FILE MOVES
FORWARD AND UP WHILE
THE HANDLE MOVES
FORWARD AND DOWN.
A FLAT, HAND OR HALF
ROUND FILE MAY BE USED.

16. USING A SAFE EDGE FILE
TO CUT A CORNER
SAFE EDGE FILE
WORK
FILE
EDGE NOT TO BE DAMAGED

17. File Card
When filing the soft metals,
the small pieces of metal will
tend to clog the teeth. If the
file is not cleaned, this small
piece of metal will scratch on
the surface of the work. We
call it pinning.

18. This case is frequently
appeared when applying
a new smooth file on the
soft metals. The pinning
can be removed with a
File Card.
File Card

19. File Card

20. QUIZ
IF THE STATEMENT IS TRUE SELECT “T”, IF FALSE SELECT “F”.
1 FILE BLADES ARE MADE FROM HIGH CARBON STEEL.
2 THE LENGTH OF THE FILE IS MEASURED FROM THE TIP TO THE
TANG.
3 THE HAND FILE IS THE SAME AS THE SAFE EDGED FILE.
4 AS A RULE THE FILE TEETH SHOULD BE CLEANED AS SOON AS
THEY BECOME PINNED.
5 IN DRAW FILING THE FILE IS HELD AT 90 DEGREES TO THE
WORK.
6 THE CUT OF THE FILE IS THE SIDE OF THE FILE.
7 THE GRADE OF THE FILE IS THE COARSENESS OF THE TEETH.
8 IN CONVEX FILING THE TIP OF THE FILE MOVES FORWARD AND
DOWN.
9 A DOUBLE CUT FILE IS MORE SUITABLE FOR ROUGHING A PIECE
OF WORK.
10 THE FILE SHOULD NOT BE STORED IN WATER TO KEEPIT COOL.