Intermediate guide sleeve

In guide‑post and guide‑bushing assemblies, the application of guide posts is becoming increasingly widespread; however, to ensure reliable performance, the structural design must meet the relevant technical requirements. The following analysis outlines these technical specifications, with the hope that mold‑component manufacturers will find it useful as a reference.

To meet the technical demands of modern societal structures, it is first necessary to select appropriate materials. Typically, the chosen material should feature a hard, wear‑resistant circular surface and a tough yet fracture‑resistant core. Consequently, in most cases in China today, companies employ 20 steel, with its surface subjected primarily to carburizing and quenching. Alternatively, T8 or T10 steels may be selected, offering a hardness of approximately 55 HRC.

After selecting an appropriate material, designing the diameter and length of the guide pins to suit the specific application can be highly critical. Typically, when the diameter of the guide pin ranges from 12 to 63 mm, the diameter of the guide bushing and the width of the template should be maintained within the range of 0.06 to 0.1.

Typically, in most cases, the guiding portion of the guide should extend approximately 6 to 10 millimeters above the convex surface; the primary purpose of this design is to prevent the core from entering the mold cavity.

In addition, we have also established a surface roughness specification. Based on experience, the guide‑surface roughness is typically denoted by the letter r and specified as 0.8 µm, while the sliding surfaces are specified as 0.4 µm Ra. When selecting appropriate tolerances, ensure reliable fixation.

Moreover, our country must also undertake the scientific and rational design of the guide‑post geometry. To ensure that the guide post and guide bushing smoothly enter the guide hole, the front end of the guide post is typically designed in a conical or hemispherical shape. Given the greater machining complexity of a hemispherical profile, a conical design is generally preferred.