Tooling Makes the Difference in Buttress Threading of Stainless Steel

Stainless steels can be one of the more difficult materials to machine, but selecting the proper tooling for the application can make the difference. In a recent project at Bent Engineering (Pohang, South Korea), four separate shale gas blocks made of 17-4PH 900H stainless steel required Buttress threading of 15 holes each for a tight hydraulic seal to handle the transmission of heavy force during operation. Wet machining was successfully performed on all 60 holes using a Doosan DBC130II moving column NC boring machine with a high-torque spindle head for heavy duty cutting.

Tooling selected from Advent Tool & Manufacturing Inc. (Antioch, IL) included a through coolant SMH4015TA8-F8 Helical Shell Mill Holder (4 in cutter), hardened and ground with a 10 deg helix and used with ITH4015-4B7/45-15NR Buttress thread carbide inserts, 1-4 pitch, .250 in thick with a locking angle. Threading each of the 60 holes required four toolpaths cutting at a feed rate of 1.57 ipm at 125 rpm and 131 SFM.

Advent Tool & Manufacturing Inc., 710 Anita Avenue, Antioch, IL 60002, 847-395-9707, Fax: 847-395-9607, info@advent-threadmill.com, www.advent-threadmill.com.