Bolster Plates


PGI Steel specializes in flame-cutting, Blanchard grinding, surface grinding and machining steel plate products including steel bolster plates.  Bolster plates normally have t-slots or scribed lines running in parallel the length of the bolster plate. There are many variations in size, dimension, and functionality for steel bolster plates.  Engineers and tool makers custom design bolsters to meet specific applications.

These plates are normally thicker than 2″.  We flame cut, then stress relieve A36 structural plate in order to improve the grinding and machining processes. Though, often times specifications suggest a Blanchard ground to ± 0.005″ tolerance thickness and a ± 0.005 – 0.010″ parallelism tolerance, relaxing tolerance levels may save time and money.  Of course, critical, close tolerances can also be achieved.

CNC Vertical Machining Centers

Our precision machine shop runs four CNC vertical machining centers.  Maximum capacity for our Johnford (VBM) vertical bridge mill is 42” height x 109” wide x 162” long at 26,400 lbs. Our Takumi CNC machine is 31″ Z-Axis x 78″ Y-Axis x 122″ X-Axis at 22,000 lbs. We installed a new Doosan Hybrid Bridge Mill in in June of 2020. It’s capacity is 98.5″ Y-Axis x 167″ X-Axis x 31.5″ Z-Axis and can handle up to 32,500 lbs. In Q4 2022, we are installing a new Doosan DBM 2550 with 206″ X-Axis x 98.5″ Y-Axis x 43″ Z-Axis that can handle up to 44,000 lbs. on its table! 

Most of these plates require a high-level of expertise when it comes to finishing reamed holes, cutting grooves, beveling or chamfering edges, and end milling or face milling. We can also provide a detailed inspection report using our Renishaw probing system.  In addition, our Takumi is also capable of horizontal milling edges upon the same piece with the installation of the 90° right-angle head.