The First Choice for Thread Milling

AT-1 thread mill enhances processing efficiency in hydraulic valve production

Hao Tian | OSG Shanghai

Thread milling often involves long cycle time and problems of deflection. In order to resolve these common obstacles, OSG has developed the AT-1 thread mill for high-quality threading, with two patented technologies registered in Japan for its tool geometry. The first patented technology is the AT-1’s left-hand helix geometry. Conventional right-hand helix thread mill is vulnerable to deflection as the cutting process begins from the tip. In contrast, the AT-1’s right-hand cut and left-hand helix geometry begins the cutting process from the shank side, thereby minimizes deflection. The second patented technology is the unequal spacing and variable lead flute geometry, which is commonly applied in end mills. The unequal spacing and variable lead flute geometry minimizes chatter. Applying the unequal spacing and variable lead flute geometry in thread mills involves a high degree of difficulty because the thread pitch has to been adjusted accordingly to the flute geometry, which requires special manufacturing techniques.

Thread milling often involves long cycle time and problems of deflection. In order to resolve these common obstacles, OSG has developed the AT-1 thread mill for high-quality threading, with two patented technologies registered in Japan for its tool geometry.

Recently, a manufacturer based in Nantong, Jiangsu Province, China, whose name cannot be disclosed due to confidentiality reasons, was able to leverage the AT-1’s superior thread milling performance in its hydraulic valve production. Founded in 1996 and currently employing approximately 300 staff, this customer specializes in the manufacturing and sales of hydraulic control systems, electrical control systems, hydraulic components, hydraulic machinery, hydraulic accessories, pneumatic parts, and more.

The customer was seeking new tooling solutions to improve the processing efficiency of its valve body production, which the company has been manufacturing since 2020. These hydraulic valves are made of S45C and has an annual production volume of 50,000 pieces.

This customer was seeking new tooling solutions to improve the processing efficiency of its valve body production, which the company has been manufacturing since 2020. These hydraulic valves are made of S45C and has an annual production volume of 50,000 pieces. More than 30 holes in various sizes are required to be threaded per valve body. Each bottom hole is a stepped through-hole. The depth of the threaded hole on the valve body part is very close to the bottom of the hole, so spiral taps cannot be used as there is not enough room for the chamfer. The machine used for processing is a Doosan vertical machining center BT50. Water-soluble coolant is applied during machining and a hydraulic holder is used. The customer was originally using a domestic cutting tool brand for the application. With the existing thread mill, corrections needed to be made multiple times during processing, which affected the overall machining efficiency.

The machine used for processing is a Doosan vertical machining center BT50 with water-soluble coolant and hydraulic holder.

OSG’s applications engineer learned of the situation during a regular customer visit. Considering that S45C is a relatively easy-to-cut material, OSG recommended the AT-1 M10 x 1.5 thread mill (EDP# 8331007) and arranged a trial opportunity through a distributor.

With the combination of the AT-1’s superior performance and OSG’s on-site technical support, processing time was halved in the hydraulic valve thread milling application.

For the first cutting test, the AT-1 was used at a speed of 3,300 min-1 and a feed rate of 0.03 mm/t. Several parts were processed, but performance was unstable, with the size of the threaded hole being either too large or too small. Upon a detail evaluation of the cutting condition, OSG’s applications engineer recommended adding an additional pass with a radius offset amount of 0.165 mm in the follow-up, which successfully stabilized the machining. The original thread mill required four cuts for each threaded hole. The AT-1, on the other hand, only needed two cuts, which halved processing time and improved the overall processing efficiency. With the cutting trial success, different sizes of the AT-1 thread mill are implemented in the application.

With the combination of the AT-1’s superior performance and OSG’s on-site technical support, this customer is about to significantly reduce processing time and hassle in its hydraulic valve thread milling application.

For more information on OSG’s AT-1 thread mill and OSG Shanghai