スレッドミルでオーバサイズのねじを加工する方法 | オーエスジー

How to machine oversized threads with a thread mill

Oversize refers to threads that are larger than a certain thread accuracy. There are various reasons for making large screws, such as plating the internal screws and anticipating deformation due to strain when the product is heat treated. In the case of taps, the tap side needs to be slightly larger (oversize) when machining oversized screws, but in thread mills, the same tool can be used by adjusting the machining path. Below, we will show you how to machine oversized threads for each scene in a thread mill.

・In the case of minor diameter correction to pass the gauge

Please keep the program as it is and adjust the diameter correction. At that time, do not remove the clamp of the workpiece to prevent misalignment.

・ When there is a specification in the drawing such as +0.3, or when the required oversize amount is known in advance

ThreadPro can handle this. In the thread type "Custom", create a program with the specified oversize amount (4 times the plating thickness before plating) added to the size of the thread. The pitch can be left as it is. The pilot hole may be in the range of the cutting tap pilot hole if there is no plating treatment. If there is a plating process, enter the value obtained by adding "2 times the plating coating thickness " from the "Cutting tap pilot hole".

・In the case of mass production processing

If you want to improve the durability of the tool in mass production, etc., it is recommended that you select the thread type "Custom" in the thread size selection screen of ThreadPro and set the value of size (D) + the required oversize amount (4 times the plating thickness) in the size (D) input field of the thread.