The circuit distinction is a useful first filter. A complete route decision also needs the component, installed assembly and required delivered result; process names alone cannot rank a job.

Locate the supply and return functions

UNISIG’s BTA overview identifies outside supply and internal return in its single-tube arrangement. The ejector diagram below instead places supply between two tubes and return inside the inner tube. Read the gundrilling circuit for the separate internal-supply/external-return arrangement and its source.

These differences identify interfaces to investigate. They do not establish achieved tolerance, tool life or cost for the component under review. Such results need a defined installation and evidence answering that particular question.

Avoid selecting by a generic boundary alone

A nominal diameter or depth-to-diameter ratio can help locate a product family. It cannot document the required guidance, connection, usable length or machine arrangement. Keep the actual proposed tool designation with any quoted capability and retain the source’s conditions.

For an illustrative comparison, two offered routes may reach the same nominal bore but differ in the included finishing and inspection. First align those endpoints. Otherwise a route that ends earlier appears faster without delivering the same specified component.

Choose the next investigation

If the unresolved question is workpiece sealing and layout, continue to ejector installation planning. If it is cutting from solid versus enlargement, continue to head selection. If it is achieved geometry, define the measurement coverage before borrowing a catalogue quality claim.

Use the RFQ worksheet below to preserve one supplied-part and acceptance definition across enquiries. The site’s method comparison brings the other route options into that same discussion, without replacing an application-specific installation review.

Revision note

October 8, 2026: revised the technical explanation and connected reading after source review. Original publication date and URL retained.