Transferring Fastener Holes

The Task:

So, you have been assigned the task of Transferring Fastener Holes from an old or damaged sheet metal part to a new replacement component.  To be accurate, you need to ensure the hole on the new parts are concentric and precisely located with the fastener holes in the older component.

For some technicians, simply using the old component as a drill guide seems adequate. For some application this may be acceptable.  However fastener holes in the old component, may be oversize or elongated .

You may unintentionally copy the inaccuracy to the new component.

The Solution:

If you want to maintain accuracy use a “Transfer” Drill Bushing. This will ensure the new fastener hole is accurately located and concentric with the desired faster hole location. 

We specifically designed our 27 Piece OD Drill Bushing Set to assure the accurate transfer of holes.

27 Piece ID Drill Bushing Set
27 Piece ID Drill Bushing Set

27 Piece OD Drill Bushing Set

We have designed the OD (Outside Diameter) of each Drill Bushing to accommodate fastener diameters used in the aircraft industry. The Drill Bushings in this set fit standard, oversize and under-size fastener holes.


The location of the fastener hole is transferred using this drill bushing as an aid . The bore of the Drill Bushing accurately guides a “pilot” drill through the new component.

Drill Bushing with an OD of 0.1875″ or less, have a bore machined for a #40 pilot drill size.

Drill Bushings with an OD greater than 0.1875″, have a machined bore for a #30 pilot drill size.

Now the Pilot Hole is Drilled:

With the pilot hole accurately located and drilled in the new component, it is time for the next step.

The next step uses standard drills, step drills or even reamers to finished fastener hole diameter.

The application’s specification may even require a combination of hole-making tools.

In conclusion, to learn more or to order tools on-line follow the link below:

https://www.sas-canada.com/store