Sourcing oversize AN & NAS bolts

[Greg Pixley]

I plead the 5th. There is a lot of free software out there that allows you to do invoices and create logos. Oversized bolts was a tough nut to crack, glad you found an easier solution.

Pix

[Jinkers]

Had to create a shell company to buy them since aerospace suppliers would only sell to companies. One of the sizes cost me $50 a bolt!

Never thought of that! Did you actually create a legal company, filing paperwork and all, or just make up a name to tell them? That's a lot of work for a few bolts

[Greg Pixley]

Scott,

Where were you when I needed you?!? I made some holes that I wasn't happy with during spar construction also. Ended up buying 15X, 18X, and 19X. Had to create a shell company to buy them since aerospace suppliers would only sell to companies. One of the sizes cost me $50 a bolt!

I still have 2- 18X and 5 - 19X if someone needs them. And I'm reasonable too...I'll just forget where they are.

Pix
Panther S/N 35

[Jinkers]

Paul,

Thanks for the help and the additional information!

Hi Jinkers, I had a hole in my horizontal spar where it attached at the front mount position that I was not happy with because it was a sloppy fit.after a little research I got a 6.3 mm bit and oversized the hole . With an AN 4 bolt it gave me a .004 interference fit. I don’t know if this will help you were you are on your spar but I wanted to throw it out if it will help.

Jimmy, like I said it's a long story and has been going on for a couple of months...

I discussed using AN4's with Dan and he didn't think that it was a good idea to go that large. His first suggestion was that a 5mm bolt would work. But I could not find a partial thread 5mm bolt with the appropriate dimensions, either there would be threads in the shear plane or I would need a couple of washers and then cut it down to size. And that was for the hex head bolts. The flat (countersunk) bolts couldn't be had in the correct length except in plain steal with no plating.

It's too bad that the AN and NAS oversizes are not available (actually some are but not the lengths I needed). However, the HI-LOKs for the qty. I need will do just fine.

As a side note, I had to order a minimum of 5 ea. I have 3 of the HL65PB6-15 (NAS7403-15 replacement) and 1 of the HL64PB-18 (NAS6603-18 replacement) if anyone needs one.

[at7000ft]

Sourcing oversize AN & NAS bolts – because I didn’t follow directions.

It’s a long story but here is the reader’s digest version…

.....

Here is a link to the HI-LOK specs:
http://www.lisi-aerospace.com/products/ ... i-lok.aspx

Happy building!

The description says:

"developed for high strength and temperature applications in today’s high performance aircraft and missiles"

so they should be perfect for the Panther.

rh

[jamesmil]

Hi Jinkers, I had a hole in my horizontal spar where it attached at the front mount position that I was not happy with because it was a sloppy fit.after a little research I got a 6.3 mm bit and oversized the hole . With an AN 4 bolt it gave me a .004 interference fit. I don’t know if this will help you were you are on your spar but I wanted to throw it out if it will help.

[psalter]

Glad you were able to find the Hi-Loks.

For builders who haven't heard of them, Hi-loks are quite common in large military and commercial aircraft, and a neat piece of hardware to use, however there are some things to know.

Hi-loks are available in a large variety of material including some you have probably never heard of (anyone ever used Waspaloy), with several types of heads, and many collars.

H-Loks are semi-permanent hardware, as stated, when the right torque is reached (no torque wrench required), the collar snaps in half and the wrenching flats portion pops off. Collars can be removed later with special tools and sometimes vice grips.

Hi-loks can be installed with basic tools, but one thing to watch. You hold the pin with an Alan wrench on the same end as the collar, which allows you to work on one side only. No reaching around the spar, but, unless you have a ratchet with a clearance hole for an Alan wrench you will be limited to open/closed end wrenches for installation. There are special ratchets available, including powered ones, but some standard tool companies have ratchets that allow a bolt or screw to extend through the ratchet which will work also.

Head styles are available in Tension heads and Shear heads in both protruding and flush styles. Tension heads are larger/stronger than shear heads in the axial direction thus the name tension. In flush styles a shear head is the size of a similar MS20426 rivet, while a tension head is the size of a screw head.

Hi-loks are typically stronger than the bolts or rivets they can be used to replace. However, like bolts, the holes need to be fairly close tolerance to work properly.

Also as stated, they are typically more expensive and sometimes harder to find (none at Aircraft Spruce) than standard bolts and hardware, which is one of the reasons not many kit manufacturers use them. In large quantities the price comes down, and the one sided installation can sometimes mean one less person needed, which reduces labor costs for installation, thus the reasons military/commercial uses them.

[Jinkers]

Sourcing oversize AN & NAS bolts – because I didn’t follow directions.

It’s a long story but here is the reader’s digest version…

I accidently drilled a few of the spar holes meant for bolts with a #10 bit instead of the recommended #16 bit and then ream. The holes were meant for NAS7403-15 and NAS6603-18 bolts. They fit pretty loose in the #10 hole. I discussed this with Dan Wessman and he suggested that the fix was to use first oversize bolts (NAS7403-15X and NAS6603-18X). However, nobody seems to carry these and I was not even able to find a place to special order them. Dan tried his suppliers and was not able to find them either.

Dan and Paul provided me with an alternative to the AN and NAS oversize bolts, HI-LOK Pins and collars. These are basically bolts and nuts (what they call collars) that the end sheers off of when the correct torque is reached. They are expensive but I was able to find them in the 1st oversize I needed.

A web search will bring up a lot of results but I was able to find them in stock at Genuine Aircraft Parts and Davis Aircraft.

Here are the appropriate part numbers:

NAS7403-15 = HL21PB6-15
NAS7403-15X = HL65PB6-15 (1st oversize)
NAS6603-18 – HL20PB-18
NAS6603-18X – HL64PB-18 (1st oversize)

The Collar (nut) for these are:
HL86-6 for the standard
HL87-6 for the 1st oversize

Here is a link to the HI-LOK specs:
http://www.lisi-aerospace.com/products/ ... i-lok.aspx

Happy building!