Files lesson

Filing

1. Mechanical Engineering Technology. Lesson Topic: Files. Objectives At the end of the lesson students should be able to: State the uses of files. Identify the parts of files Identify various shapes of files State and define three methods of filing. State how to care for files Explain some terms used in filing. 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 handle teeth

4. Shape of files CROSS SECTIONS flat Half round round knife triangular square 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.