【 Summary Description 】 Bar is made by heating, rolling, cooling, and cutting steel billets. The finished product inspection of bar materials requires checking the geometric dimensions and determining whether they are straight.

Rod is made by heating, rolling, cooling, and cutting steel billets. The finished product inspection of bar materials requires checking the geometric dimensions and determining whether they are straight.

So how to measure whether a rod is straight or not?

The straightness tolerance refers to the total allowable variation of a single actual straight line, and is also an important criterion for measuring whether a line is straight or not. How to measure straightness?

1. The straightedge method uses the measuring surface of a quartz ruler as a known plane to compare with the measured straight line, and records the contour shape of the measured section or prints out the straightness error through electrical length sensors, corresponding electronic components, and recorders.

2. Measure straightness error using an optical collimation telescope system. The collimated telescope system consists of a collimated light tube and a telescope. The light emitted by the light source passes through the reticle 1 and objective lens 1, and then exits as parallel light. After passing through the objective lens 2 in the telescope, it converges on the reticle 2 located on its focal plane and is read through the eyepiece.

3. Measure with an autocollimator. Divide the measured total length into several sections and measure the inclination angle of each section. Calculate the straightness by drawing or calculating.

4. Measure straightness using the gravity phenomenon of liquid automatically maintaining horizontal or heavy objects automatically maintaining vertical. The commonly used measuring instrument is a level.

5. Measure straightness using steel wires and laser beams. When measuring the straightness error of the lathe guide rail using steel wire, moving the slide can read the deviation values of each point of the guide rail from the steel wire from the reading microscope installed on the slide.

Used to measure the straightness of cylindrical lines or axes.