The International Cessna^® 170 Association

Ragwing Guys - Can anyone tell me what type of bolt is used to attach the rear lift strut to the wing? The parts manual lists part no. 0422297, which I've found for the bargain price of $73.00 each. I'm curious as to what makes this bolt so special when all of the other strut bolts are listed with AN part numbers. I don't have the old ones to compare to as the airplane was disassembled when I bought it. Any help would be appreciated.

Thanks!

-D

While your at it make sure you noticed that the nut is a special half nut or low profile nut. Then be particularly carefull that you have enough threads showing after you tighten it. Bill k

Also known as a "shear" nut . (AN365 type)

N2520V wrote:what makes this bolt so special

It is a shoulder bolt.
For those who do not understand, it is a bolt with a smaller diameter in the threads.
When you tighten up the nut, it clamps the bolt and not the strut allowing the strut to move.

A picture is worth a lot of description. This is not the bolt in discussion, but is a shoulder bolt.

Does not look like a Shoulder Bolt in this picture from the 140 Forums. (click on the picture to see a close up view of the Bolt)

John how could you tell from that picture it's not a shoulder bolt? I don't think you can.

Here's a picture from one of the links I posted earlier. It shows the bolt is not a shoulder bolt.

I just pulled the two bolts that I purchased from Premier 2 years ago.
Correct, they are not shoulder bolts. It has been two years The shoulder bolts are elsewhere in the wing.
I paid $70 each, so the price has not changed too much in 2 years.

These bolts are made to a Cessna drawing (thus very low volume).
The gage length and thread length appear to be tightly controlled.
This is to ensure that the shank of the bolt rests on both brackets with the thread run very close to the bracket.
The thread length is short to control the length between the strut bracket and the wing frame.

A quick check of my supply of AN bolts could not find an equivalent bolt. The threads would be resting in the bracket, or the length was too long.

One of the big problems with AN bolts is that the gage length is not controlled, the length is.
Boeing designed their bolts opposite, we control the gage length because that is what you need to determine and then added threads on beyond that.

Sometimes specially parts-numbered hardware that resemble common AN or NAS or MS hardware is subjected to additional testing standards or mfr'g processes. (Usually NDT tests such as X-ray or magnaflux, etc.) I recall a Baron with elevators which moved in relation to each other due to a common AN bolt installed where a physically identical bolt with a special part number was actually required. They looked the same, and that's why someone may have previously substituted it, but they are NOT the same.