When people think about trepanning they typically envision large, deep, round holes or hollowing of bar stock, but at TCI Precision Metals we provide a variation of trepanning, using plate stock, that we call Shallow Trepanning™.

Typical trepanning is the process of drilling a large deep hole in a metal part leaving the core intact.  Once the drilling is complete the core can be removed along with the chips to be recycled or used for other purposes.  This saves time, money and energy as the entire core is not reduced to chips. The most common trepanning application is a long through bore, resulting in a custom metal tube.  If concentric rings are the objective, the tube can be cut into specified thicknesses. Trepanning can be used to create a range of holes, but the process described is typically used to produce holes from 4.1” to 15.75”.  Below or above these ranges other processes are employed, but customers still use the term trepanning to describe the outcome they are looking for if large diameter holes are involved. Trepanned parts are most commonly used in heavy equipment manufacturing, oil and gas industry, and aerospace. Though many trepanned parts are cylinder-shaped this is not a requirement; the process can be applied to virtually any shape part.

Trepanning Applications

  • Weight reduction in finished parts
  • Pistons or cylinders
  • Fluid ports
  • Seals and more

At TCI Precision Metals we use our method of shallow trepanning in the production of precision Feature-Added Machine-Ready Blanks, for example, when customer specifications require plate stock with large diameter holes or circle features, machined to close tolerances. Round flat blanks with a through or blind hole, concentric rings, and discs are all considered trepanned parts.

At TCI Precision Metals we trepan aluminum, stainless steel, and other alloys in the process of producing many different types of Machine-Ready Blanks, roughed parts, and finished machined parts, based on an understanding of what the customer is looking to accomplish.  Things to consider when talking to us about trepanning, include:

What material and heat treatment is required?
If the material is being supplied, is it bar stock, forgings or castings?
What are the specifications and tolerances for the trepan feature?
Are there concentricity requirements?
Are there any surface finish requirements?

Founded in 1956, TCI Precision Metals is a family-owned precision manufacturer producing precision Machine-Ready Blanks from aluminum, stainless steel, and other alloys. Sawing, Grinding, Milling and Finishing operations with the added benefit of being a plate and sheet distributor make TCI Precision Metals a one-stop source for quality aluminum, stainless and other alloy blanks. TCI Precision Metals offers customers rough CNC milling and turning services when large amounts of material need to be removed or features added to solid parts or castings. Complete-to-print components can also be produced.

Thanks for reading -


Leave a Reply

Your email address will not be published. Required fields are marked *

Let's Get Started!

Request A Quote

Recent  Blog