Do you know the difference between Planetary Thread Rolling and Flat Thread Rolling?

Do you know the difference between Planetary Thread Rolling and Flat Thread Rolling?

• Admin
• 2024/10/25

Today we will focus on planetary dies and flat thread rolling application and difference.

The processing method of plastically deforming the workpiece with a forming rolling die to obtain a thread. Thread rolling is generally carried out on a thread rolling machine or an automatic lathe with an automatic opening and closing thread rolling head. It is suitable for mass production standards external threads of fasteners and other threaded connections.

The outer diameter of the rolled thread is generally no more than 25 mm, the length is no more than 100 mm, and the thread accuracy can reach level 2 (GB197-63). The diameter of the blank used is roughly the same as the pitch diameter of the thread being processed. Rolling generally cannot process internal threads, but for soft workpieces, non-slot extrusion taps can be used to cold extrude internal threads (the maximum diameter can reach about 30 mm). The working principle is similar to tapping. When cold-extruding internal threads, the required torque is about twice as large as tapping, and the machining accuracy and surface quality are slightly higher than that of tapping.

According to the different rolling dies, thread rolling can be divided into two categories:  planetary thread rolling and flat thread rolling.

Flat thread rolling: the two thread rolling plates with thread tooth form are staggered by 1 / 2 of the screw pitch, and the static plate is fixed, and the moving plate moves in a reciprocating straight line parallel to the static plate. When the workpiece is fed between two plates, the moving plate rubs the workpiece forward to form a thread due to plastic deformation on its surface.

There are three kinds of planetary thread rolling: radial rolling, tangential rolling and rolling head rolling.

Radial thread rolling: two (or three) thread thread rolling wheels are installed on the parallel shafts, and the workpiece is placed on the support between the two wheels. The two wheels rotate in the same direction and at the same speed, and one of them also makes radial feed motion. The workpiece rotates under the drive of the thread rolling wheel, and the surface is extruded radially to form thread. For some lead screws with low precision requirements, the similar rolling forming method can also be used.

Tangential thread rolling: also known as planetary thread rolling, the rolling tool is composed of a rotating central thread rolling wheel and three fixed arc wire plates. During wire rolling, the workpiece can be fed continuously, so the productivity is higher than that of thread rolling and radial rolling.

Thread rolling head thread rolling: it is carried out on an automatic lathe and is generally used to process short threads on workpieces. In the rolling head, there are 3-4 thread rolling wheels evenly distributed around the workpiece. During thread rolling, the workpiece rotates and the rolling head feeds axially to roll the workpiece out of the thread.

If you have more to say about thread rolling, please leave a comment below, welcome to discuss together!

• SEER Insert
• RPHX High-temp Alloy Insert
• APKT11T304-PM YBC302
• JDMT070204R
• TNMG160408N-EX AC630M