AR70/90 Front Trunnion Tab Repair Kit

Description

This kit contains two laser-cut 4130 alloy steel tabs to replace the tabs that were torch-cut off your AR70/90 front trunnion.  They will need to be trimmed to fit what remains of your original tabs and will need some polishing inside the holes to open them up to exactly 7.0mm. Due to manufacturing tolerances, we chose to go just the slightest amount undersize to let each builder choose their own level of fit and finish, rather than sticking you with a potentially sloppy fit!

The tabs are 0.125″ thick, as opposed to the original 0.110″ thickness. This is partly for manufacturing convenience and partly to allow you to weld the tabs on, and then machine to correct for minor misalignment and clean up any cosmetic welding issues. If you choose to center the tabs, you can machine both inside and outside the tabs and hide all welding. These tabs are perfect to go with your AR70/90 Receiver Flat and Rear Takedown Block.

Your front trunnion is made from hardened alloy steel and must be kept below 250F except as close to your weld as possible. It is highly recommended that you TIG weld your tab repair kit on using ER80S-D2 filler rod. You are responsible for checking the hardness of your trunnion before and after welding-and I highly recommend you do so!