Aero precision takedown pin set screw

[submin]

I finally got the courage to build my own AR. Since it’s my first, I ordered a X15 budget priced lower and currently have the pivot pin, mag release and bolt catch installed without a scratch, gouge or scuff. Wonderful. Trigger is ordered and I’m waiting until after it is installed before installing the selector lever as the Geissele I installed in my Colt had clearance issues. My question is with the threaded takedown pin detent and spring set screw. Or, should I say, the correct hex key size. Smallest key I have is 1/16th inch. If any readers know for certain I’d greatly appreciate a shoutout. Tnx.

 

[Blue68f100]

Always use the correct size tool for the job. I don't have their lower but I have not seen any smaller than the 1/16" unless it's a metric size. And everything I have on my AR's are SAE. I prefer the Bongus Ball end allen wrenches. Allows you to turn the screw easier.

 

[submin]

The correct size tool for the job. Exactly. I really want to do a complete first assembly and have zero scratches or buggered screw heads. I’ve watched sooo many YouTube assembly videos where supposedly seasoned assemblers left deep scratches installing the bolt catch. Tape isn’t good enough by itself so I taped an old motel room swipe card to the receiver to make sure. No scratches. As for the takedown pin set screw, if it is that unusual size I’ll omit and assemble as a normal receiver. No biggie. Thanks again.

 

[a5werkes]

The standard holes are perfect for a 4-40 tap wrench, shorten the spring the length of the screw and then I use a 4-40 set screw that requires a 0.05" or 1.3 mm hex tool.

 

[Shimitup]

I've got an old Elkind fold up set that goes down to .050. I haven't noticed if they still sell those or not. I have a second Elkind set that does not include the .050 size.

 

[submin]

Yes. It is a 4-40 set screw. Thank you very much gentleman. Now I have to locate a 1.3 mm or 0.05” hex key. This really is optional if I use the set screw or not. AP designed it in. I will probably use it. but I’m old school. When I think AR platform i envision brave men carrying 20” light weight barrels and triangle Handguards using Viet cuss words. The fence work on the receiver isn’t correct but close enough. Thanks again

 

[Blue68f100]

A good industrial supply house will have the sizes your looking for. I have Allen wrenches down to 0.030" and smaller, I've only used them once on some special instruments. If you have an Elliot's hardware near you they will have them, maybe an Ace hardware too.

 

[submin]

I picked up this set while the wife was in her clothing store this morning. https://m.lowes.com/pd/Kobalt-22-key-Metric-Standard-SAE-Hex-Key-Set/50385572Shame to spend on yet another set just for one key I didn’t have. I have one now.

 

[Kp321]

Every set of Allens I have include a 0.050" wrench. They should be readily available.

 

[n6yga]

You can get single allen keys on Amazon. But, most sets that I have seen have a .050. Now, the .028 is a little harder to find...

Mark.