The fitter must know what to do with the small hammer in the fitter.

1) Check the size and shape errors of the blank and determine the machining allowance;

2) Machining the first surface requires flatness of 0.04㎜ and roughness Ra3.2.

3) Processing the second surface requires verticality of 0.05㎜, flatness of 0.04㎜ and roughness Ra3.2.

4) Machining the third surface, ensuring the dimension ㎜ and parallelism < 0. 15 ㎜, and meeting the requirements of verticality < 0.05 ㎜, flatness < 0.04 ㎜ and roughness < < Ra3.2;

5) Machining the end faces perpendicular to the first and second faces, with verticality < 0.05 ㎜ and flatness < 0.04 ㎜;

6) according to the end face and the first face, draw the machining boundary in the shape of a hammer, and saw off the surplus;

7) Machining the fourth surface, ensuring the dimension ㎜ and parallelism < 0. 15 ㎜, and meeting the requirements of verticality < 0.05 ㎜, flatness < 0.04 ㎜ and roughness < < Ra3.2;

8) Ensure that the total processing length is 84 0.5 ㎜;

9) processing inclined plane, and reach the size of 25, 3㎜, but also ensure the verticality < 0.05 ㎜, flatness < 0.04 ㎜, flatness < Ra3.2 requirements;

10) Draw the processing boundary of 8-2× 45 chamfer and 4-R2 according to the drawing requirements, first process R2 with a circular file, then process 2× 45 chamfer with a plate file, and connect smoothly; (This step demonstrates)

1 1) Draw the processing position line of the hole (as shown below) according to the drawing requirements, drill φ 8.0, and then file the long round hole;

12) All accuracy shall be rechecked, necessary trimming and filing shall be carried out, and sharp corners shall be deburred and passivated.

Second, matters needing attention

1) Pay attention to two points when practicing: First, the operating posture and movements should be correct; Second, the direction and size of hands should be changed correctly and skillfully. Always check the straightness of processing with a knife ruler, improve the stress form of your hands, gradually form the skill of filing, correct problems in time when found, and overcome blind and mechanical practice methods;

2) When drilling with φ8mm drill bit, it is required that the drilling position is correct and the aperture is not obviously enlarged, so as to avoid insufficient machining allowance and affect the correct machining of screw holes;

3) Waist holes can also be made (φ 10mm, hole spacing 10mm). First, drill with φ9.7mm drill bit, which requires that the drilling position is correct and the aperture is not obviously enlarged, so as not to cause insufficient machining allowance and affect the correct machining of waist hole. When filing the waist hole, file both sides of the plane first, and then file the cambered surfaces at both ends. Pay attention to control the lateral movement of the file when filing the plane to prevent the file from damaging the hole surfaces at both ends;

4) When machining a concave arc with an angle of R3.5mm, the horizontal file should be filed accurately, and then it is easy to push the light, and it is not easy to collapse at the back arc tip angle;

5) When machining R2mm and C2mm, the transverse direction must be straight and perpendicular to the side, so that the cambered surface can be connected correctly and the appearance is beautiful;

6) Pay attention to measurement methods and gestures to ensure the correctness of measurement;

7) Correct use of measuring tools and civilized and safe operation.