Thread repair

[jpayne]

Guys,
Can I put a M12 helecoil into what was a 7/16 unf hole.
One of the brake caliper threads on a pair of 2.8i bilstein struts is damaged and I don't think its repairable without helecoiling or similar.
I believe it will be fine as after the new oversized hole is drilled there is none of the old thread left.
But need a logic check
also what material are the 'cast' parts of ford struts
Cheers

JP

[MOOSE]

[jpayne]

Thanks John, dont know what any of that is. I have a m12 helecoil kit and plenty of inserts. But will they work with an original 7/16 hole and in the cast material that is a ford strut knuckle.

Cheers

JP

[Danny M]

Justin I would just try retapping the hole for a 12x1.75mm thread as a 7/16"unf thread needs a 9.9mm pilot hole and a 12x1.75mm takes a 10.2mm
If then it still looks ordinary then run the Helicoil tap through and yes the forging will handle the increase diameter thread cut into it but make sure it is dead straight as I would be ultra careful so that it pulls up straight when tightened

[jpayne]

Thanks Danny,
Yeah will be using the pedestal drill to get the hole square, straight and plumb, as I have same concern re bolt doing up square.

Justin