BSF Manual – Backspotfacing without blade activation using coolant or compressed air

Product innovation, Balgach 04.07.2024

Counterboring on the back side of the bore regularly presents a challenge, as access to the machining area is difficult. The BSF from HEULE provides a reliable solution: access is provided through the bore itself. The tool is now also available with the option of manual blade activation instead of using coolant or compressed air.
As a technology leader in the field of back bore machining, HEULE has been offering first-class solutions not only for deburring or chamfering, but also for backspotfacing for several years. As machining is performed from the front side of the bore, counterbores can also be easily produced in hard-to-reach areas. The BSF tool solution guarantees the process reliability that is crucial for serial production and this for counterbores up to 2.3x the bore diameter.

New variants in activation

The high level of efficiency is based on the robust and simple operating principle. After activating the spindle at a defined RPM, centrifugal force causes the carbide blade to fold out. HEULE offers several options for retracting the blade after machining. The standard version uses internal spindle coolant (min. 20 bar) for retracting, while the BSF Air uses compressed air (min. 5 bar).

Customers contacted HEULE with the need to be able to use the BSF on simpler machine types or for workpiece materials which do not allow the use of coolant. This led to the development of a further BSF version that complements the standard range with the option of manual blade activation – the BSF Manual. In this version, the blade can be retracted “by hand” using the activation ring. Thanks to the modular design, existing tools can be modified to manual activation if required.

Backspotfacing in automated operations

The BSF tools machine bores in the standard range from a diameter of 6.5 mm to 21.0 mm. They are extremely easy to assemble and therefore ready for use in a very short time, with no need for any further pre-setting. The folding mechanism of the blade in combination with the robust design guarantee the required process reliability. Whether aluminium, high-alloy steels or Inconel and titanium, the tool can machine a wide variety of materials.


The new BSF Manual with manual activation ring is used when the process does not allow machining with coolant or compressed air.

The proven operating principle: Folding out of the blade due to centrifugal force; retraction either via internal coolant, compressed air or now “by hand”.

Backspotfacing eliminates the need to reclamp the workpiece, which not only enhances efficiency but also precision.

BSF can be used in very limited spaces. Access to the machining area is only possible through the bore itself.

Media contact:

Jasmin Hutter
Head of Marketing
HEULE Werkzeug AG
Tel. +41 71 726 38 27
Wegenstrasse 11, 9436 Balgach, Schweiz

Swiss Machining