Tap for tie down AEX

[CaptPausert]

I am getting ready to order a tap to tap the tie down block on the wing. Is it worth getting a tap set or are there few enough locations for tapping threads on the fuselage that it is better to just order the single tap?

Thanks

 

[wirejock]

Tap

I am getting ready to order a tap to tap the tie down block on the wing. Is it worth getting a tap set or are there few enough locations for tapping threads on the fuselage that it is better to just order the single tap?

Thanks

3/8-16
A good tap & die set will cost about $300. Individuals are about $8 each. I buy Irwin at Ace. Singles. I don't have anywhere near a full set.
Most common ones I use.
4-40, 6-32, 8-32, 10-32, 10-24, 1/4-20, 1/4-28 & 3/8-16
1/8 & 1/4 NPT
I also have a few metric but those are for the automotive.
I also have a Tap Socket Set
They are really handy for using a tap with a wratchet.

 

[Jonnyb]

Don’t get a cheap one, or this happens!

 

[Taltruda]

It’s all about knowing how to use a tap.. make sure you start it straight, use lube, and back out often to clear the flutes. Don’t go all the way in one shot.. you have to go forward and backwards.. go by hand and pay attention to the pressure..

 

[wirejock]

Tap

It’s all about knowing how to use a tap.. make sure you start it straight, use lube, and back out often to clear the flutes. Don’t go all the way in one shot.. you have to go forward and backwards.. go by hand and pay attention to the pressure..

What he ^ said.
You have to use oil, go back and forth and remove the tap often to clean the shards or the material will gall, jam the tap and ruin the threads. 1/4 turn in at a time. Rotate backwards. Every full turn, remove and clean.

 

[skypilot737]

Tap or not

If you don’t want to deal with tapping they do sell a pretapped version of that piece. That’s what I did and haven’t really thought about it since.

 

[wirejock]

Tap

If you don’t want to deal with tapping they do sell a pretapped version of that piece. That’s what I did and haven’t really thought about it since.

Cleveland used to sell a kit with pretapped tie down brackets and some really nice powder coated rings. Since I wasn't happy with mine, I replaced them. The second set was installed flush to the skin so the tie down ring wouldn't deform the skin.

 

[JonJay]

What he ^ said.
You have to use oil, go back and forth and remove the tap often to clean the shards or the material will gall, jam the tap and ruin the threads. 1/4 turn in at a time. Rotate backwards. Every full turn, remove and clean.

This.
Most tap sets or individual taps sold through the common retailers are three or four flute. Avoid the two flute taps as they are typically for machine tapping, stronger, but harder to start and keep straight by hand.
The flutes dictate how far you turn before you back off to “break” the chip: four flutes, 1/4 turn, three flutes, 1/3 turn, etc….
Almost any lube will work but Boelube, Kerosene, and Diesel Fuel work better than light oils.
Go slow and you will get the feel of it. You’re not making a thousand of these.
As mentioned, taps break when the chips are not broken and cleared properly.

 

[BillL]

Don’t get a cheap one, or this happens!

It’s all about knowing how to use a tap.. make sure you start it straight, use lube, and back out often to clear the flutes. Don’t go all the way in one shot.. you have to go forward and backwards.. go by hand and pay attention to the pressure..

Kinda both, I have several sets and loose taps and found that HHS (HighSpeedSteel) taps will cut with much less torque than carbon taps. And use tap magic as all the stuff we tap is softer and does not cut as easy as 2024 T3.

I would recommend individuals for the aluminum work - 6-32, 8-32 and the 3/8" for the tie downs. YMMV

 

[CaptPausert]

thanks for the tips guys. When I was at Oklahoma State during our machining class as part of the engineering program I was the only person who did not break a tap. The head of the shop made everyone use #8 taps so he could buy them in bulk. I ended up getting requests from several other groups asking me to tap the holes in their project since I ended up being the best one at it.

I really miss having access to a machine shop. They won't let me use the equipment at Tinker.