Definition
A machining process that uses a long, multi-toothed cutting tool called a broach to remove metal in a single pass. Each successive tooth on the broach cuts slightly deeper than the one before it, producing a precise internal or external shape such as a keyway, spline, or square hole.
Plain English
A way of cutting a precise shape into metal by pulling or pushing a long tool with many small teeth through it. Each tooth shaves off a tiny bit more than the last, so by the time the tool has passed through, the finished shape is complete.
Context Anchor
Seen in aircraft maintenance and manufacturing when a part must have an accurately shaped hole, groove, or internal surface.
Derivation
From the Old French 'broche,' meaning a pointed tool or spit. The cutting tool is called a broach because it is a long, pointed shaft with teeth, and 'broaching' is the act of using it.
Why Pilots Care
Broaching can quickly lead to loss of directional control, potential capsizing, or structural damage during water operations.
Analogy
Think of pulling a comb through hair, where each tooth of the comb is slightly longer than the one before it. By the time the comb has passed through, every strand has been trimmed to a precise length.
Intuition Check
Broaching does not mean bringing up a topic in conversation here. In maintenance, it means cutting or shaping a part with a special tool.
Example Sentence 1
The keyway in the propeller hub was produced by broaching, giving it the exact shape needed to lock onto the crankshaft.
Example Sentence 2
Strong crosswinds increased the risk of broaching during the water landing rollout.