Marking is a technique often used by fitters, and the marking platform is of course the most commonly used tool. Therefore, it is necessary to master the basic use of the fitter’s marking platform and the use and maintenance of the marking platform.
一. The concept of marking
According to the drawing or actual size, accurately marking the processing boundary on the surface of the workpiece is called marking. Marking is a basic operation of fitters. If the lines are all on the same plane, it is called plane marking to clearly indicate the processing boundary. If it is necessary to mark the surfaces of the workpiece in several different directions at the same time to clearly indicate the processing boundary, it is called three-dimensional marking.
二. The role of marking
(1) Determine the processing position and processing allowance of each processing surface on the workpiece.
(2) Check whether the dimensions of each part of the blank meet the requirements, and check the surface accuracy of the marking platform and whether there are foreign objects on the surface.
(3) In the case of certain defects on the blank, use the borrowing method during marking to achieve possible remedies.
(4) Cutting the sheet material according to the marking line can ensure the correct material selection and make reasonable use of the material.
It can be seen from this that marking is an important task. If the line is marked incorrectly, the workpiece will be scrapped after processing. Check the dimensions and use the measuring tools and marking tools correctly to deal with mistakes.
三. Preparation before marking
(1) First, prepare the marking platform for marking and check whether the surface accuracy of the marking platform is accurate.
(2) Cleaning the workpiece. Clean the surface of the blank or semi-finished part, such as smudges, rust, burrs, and iron oxide. Otherwise, the paint will not be firm and the lines will not be clear, or the working surface of the marking platform will be scratched.
(3) In order to obtain clear lines, the marked parts of the workpiece should be painted. Castings and forgings are painted with lime water; small blanks can be painted with chalk. Steel parts are generally painted with alcohol solution (made by adding paint flakes and purple-blue pigment to alcohol). When painting, pay attention to apply the color thinly and evenly.
Post time: Sep-16-2025