Components with mirror polish finishing are aesthetically impressive and have improved functional characteristics. However, know-how and precision are required to achieve this type of finishing. In this step-by-step guide, we will present a tried and trusted method for mirror polishing the steel 1.2343 ESR with a hardness of 54 HRC.
The following tools will be used:
Step 1 – Preparation
First, the component is carefully assessed: how was the surface pre-machined, i.e. was it milled, ground or eroded? This determines the selection of a suitable polishing stone and the appropriate grit size. In this example, the surface has been ground, which is why we will start with a polishing stone with grit size 320. Cutting fluid is recommended for optimum performance.
Step 2 – Directional polishing
To achieve the mirror finish, directional polishing is also necessary. It is mainly used for technical components to remove machining marks and improve demoulding. In the example, we switch to grit size 400 and then to 600 and always use the segment grinding method.
If directional polishing is the last step, the surface should be reworked with wet abrasive paper, otherwise this can be skipped.
Step 3 – First polishing with diamond compound
Now we use diamond compound with a grit size of 9 μ on the component. The right paste is selected depending on the material and its hardness. Further details in this regard are available in the portal. A Speed Lap set and an air file with pendulum or linear stroke should be used. If the paste is too dry, a little thinner can help.
Step 4 – Fine grinding with diamond compound
We now refine the surface with a 6-μ diamond compound and a soft lapping stick. Here, too, we turn the component by 90° after each step (i.e. segment grinding), which makes the previous work steps visible. The polishing cleanliness thus becomes evident.
Step 5 – Mirror polish finishing
Finally, we smooth the surface and intensify its shine using a 3-μ diamond compound and a goat hair brush. The smallest scratches thus become visible, which may make it necessary to return to previous steps. After the surface has been polished, we finish it with a 3-μ diamond suspension. Finally, we carry out cleaning and polishing once again with a 3-μ diamond suspension and a polishing cloth to achieve the final mirror polish.
If you require any further information, please feel free to contact us at any time.
