AR15 staking the end plate

[gudel]

I have a Yankee Hill single point sling attachment plate, and wanted to stake it to castle nut after installation, but having a hard time creating that a notch.
I tried a prick punch to make a starting point and pounded really hard. I tried to use a center punch, it wouldn't even leave a dent!
I suppose YHM hardened this sling plate. I ended up using blue Loctite. Does anyone use this mount or other single point sling plate and successfully staked it?

 

[rcmodel]

No.

But if I had one too hard to stake, I would probably try spot annealing it with a small acetylene torch tip.

rc