Spring Drill Stop

Aircraft Spring Drill Stops

Spring drill stops are designed for aircraft maintenance drilling applications where controlling drill depth and protecting the surrounding work surface are important. The spring-loaded stop attaches directly to the drill bit to help limit drill travel, cushion drill breakthrough, and reduce the chance of the drill chuck marking the aircraft surface.

A spring drill stop is especially useful when drilling aircraft sheet metal, panels, brackets, and other components where excessive drill penetration can damage material behind the workpiece. The spring provides a degree of cushioning as the drill breaks through the material, helping make controlled drilling easier for the technician.

Available in five commonly used aircraft maintenance sizes, each size is color coded for quick identification in the shop.

How an Aircraft Drill Stop Works

A spring drill stop attaches directly to the drill bit and acts as a physical stop during drilling. As the drill approaches the desired depth, the spring compresses against the work surface. This helps prevent the drill from continuing farther than intended and cushions the moment when the drill breaks through the material.

The spring also helps keep the drill chuck from contacting the aircraft surface. This can be particularly valuable when drilling finished panels or other areas where unwanted chuck marks, dents, or surface damage could require additional repair or refinishing.

Why Use a Spring Drill Stop in Aircraft Maintenance?

• Controls drill depth: Helps prevent excessive drill penetration through aircraft sheet metal and components.
• Cushions drill breakthrough: The spring provides cushioning as the drill passes through the workpiece.
• Protects aircraft surfaces: Helps reduce the risk of drill chuck marks and unwanted contact with the surrounding surface.
• Quick attachment: Attaches directly to the drill bit for convenient use during drilling operations.
• Easy size identification: Color-coded sizes allow technicians to quickly identify the appropriate drill stop.

Aircraft Drilling Applications

Drill stops can be useful during a variety of aircraft maintenance operations involving controlled drilling. Typical applications include drilling aircraft sheet metal, preparing fastener holes, installing or removing components, and performing maintenance where the technician needs to limit drill penetration.

They are particularly useful when there is a component, structure, wiring, tubing, or finished surface behind the material being drilled that could be damaged by excessive drill travel. Always follow the applicable aircraft maintenance manual, engineering instructions, or other approved procedure for the required hole size and drilling depth.

Choosing the Correct Drill Stop

Select the drill stop that corresponds with the drill bit and drilling application specified by the applicable maintenance procedure. BAC offers spring drill stops in 1/4", #10, #21, #30, and #40 sizes.

The color-coded design makes it easier to identify frequently used sizes at the workbench or in an aircraft maintenance tool kit. Keeping several sizes available allows technicians to quickly configure the appropriate drill for different fastener-hole applications.

Spring Drill Stops vs. Fixed Drill Stops

A spring drill stop provides cushioning during drill breakthrough, making it useful when both drill-depth control and protection of the work surface are important. The spring action helps absorb some of the force generated as the drill exits the material rather than allowing the drill to travel freely beyond the workpiece.