How to Repair an Aluminum Thread

by C.L. Rease
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Aluminum automotive parts are lightweight and durable. Threads cut into aluminum are prone to stripping. This tendency results in the need to install new threads to reinstall an accessory to an aluminum part. Replacement thread inserts are made of steel, offer a stronger pulling strength than aluminum threads and are less likely to strip when you install or remove a bolt from the installed thread insert. The threads replaced with a thread insert will remain the size of the original stripped aluminum threads, allowing you to reuse the accessories-supplied fasteners.

Step 1

Secure the drill bit in the chuck of a 3/8-inch drill motor. Select a drill bit size specified by the hole sizing chart from a drill bit set. Refer to the thread repair kit hole sizing chart to determine the hole size needed to install the thread insert.

Step 2

Apply cutting fluid to the drill bit and the hole containing the damaged aluminum threads.

Step 3

Drill out the damaged threads with the drill bit installed in the 3/8-inch drill motor. Apply cutting fluid throughout the drilling process to keep the drill bit from clogging with aluminum.

Step 4

Tap new threads into the drilled hole with the tap shown on hole sizing chart and tee-handle tap wrench supplied with the thread insert repair kit. Apply cutting fluid to the cutting threads of the tap to produce clean threads in the aluminum while you turn the tee-handle tap wrench clockwise.

Step 5

Turn the tee-handle tap wrench counter-clockwise to remove the tap from the now threaded hole.

Step 6

Thread a thread insert onto the end of the installation tool supplied with your thread repair kit.

Step 7

Set the end of the thread insert into the threaded aluminum hole. Turn the installation tool clockwise to thread the insert into the hole. Stop turning the installation tool when the thread insert is flush with the top of the threaded hole.

Step 8

Remove the installation tool from the installed thread insert.

Step 9

Slide a punch into the installed thread insert. Strike the back of the punch with a hammer to remove the tang from the bottom of the thread insert.

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