In order to ensure the quality of welding, the welded blade should be carefully inspected to find out the cause of the defect and improve it. Before inspection, the blade should be sandblasted or lightly ground to remove the solder and impurities adhering to the surface of the blade, and cleaned with kerosene. The inspection items and requirements are as follows:

1. Check the weld strength: Grind the back of a blade with a green silicon carbide grinding wheel and check the thickness of the solder layer. The thickness is required to be less than 0.15 mm. There should be no pores and insufficient solder on the bottom surface of the tool tip support, and the weld that is not filled with solder should not be more than one-tenth of the total length of the weld. If there are air holes, the blade will fall off during cutting.

2. Check the position of the blade in the slot: If the blade is misaligned and sags beyond the technical conditions, re-welding should be carried out.

3. Check the welding strength: use a wooden hammer or a copper hammer to strike the blade with a medium force, or use an I hammer to strike the blade with a strong force. At this time, the blade does not fall off the knife body as qualified. To check the welding strength of the blades, it is not necessary to check all of them one by one, and spot checks are also used.

Fourth, check the flatness of the blade: If there are obvious pits on the blade, it means that the blade is overheated and deformed, and the new blade should be burned and re-welded.

5. Check for cracks: After the blade is cleaned with kerosene, if there is a crack on the blade, the kerosene will penetrate into the crack and appear black lines, which can be observed with the naked eye. It can also be observed with a magnifying glass of 10-40 times.

To check the blade cracks, you can also use the color flaw detection method: use a solution of 65% kerosene, 30% transformer oil and 5% turpentine, and add a little Sudan red. Put the turning tool blade part in the solution for 10-15 minutes, then wash it with water, apply a layer of white clay (kaolin), and observe the surface after drying. If there are cracks on the blade, the color of the solution will be white clay. The upper part is exposed and can be seen with the naked eye. The cracked blade cannot be used and needs to be re-welded.