NAS1097 vs MS20426 1

[2ndThermoLaw]

Hello,

can these be substituted for each other? ie. could MS20426 be installed in lieu of NAS1097 and vice versa?

 

[Damineh]

I have been looking for allowables for NAS1097AD for a while now. As mentioned here, it can't be found in MIL-HDBK-5. Today, I came across a thread from 2004 in which SparWeb participated in and I believe you were sent Grumman and Douglas test data for this fastener. Is there any way you could share those?
I used Boeing Engineering Liaison Manual, Page 40.2.1. I figured NAS1097 and BACR15CE are equivalent but I could only find BACR15CE allowables in double sheer on Page 40.2.2. Since the material for BACR15BB and BACR15CE are the same, I used the allowable values for BACR15BB! I don't think my values are correct though.
I would appreciate any help you could provide. I've gone the Fsu and Fbru way but I want to be certain what I'm doing is correct.

Thank you.

Damineh

 

[rb1957]

i suspect that BACR15BB are MS20426DD rivets (BB is their usual design code).

for 1097AD i use the table in mil-hdbk 5 (or ar-mmpds-01) for 1097E and derate for shear strength.

 

[Sparweb]

The site administrators don't like e-mail addresses typed directly into the forum, so I'll just let you know Damineh, that my hotmail e-mail address is extreeeeeemely obvious.

RB1957, I checked the numbers, and the Grumman allowables are more conservative than de-rating the "E" allowable.


Steven Fahey, CET

 

[Damineh]

True! I compared mine with the DC10 allowable and it's higher.

Thank you.

Damineh

 

[planedr]

Bacr15BB rivets are protruding head MS20470. The main difference between a CE and a 1097 is the fastener coating. The CE designation has been superceded by BACR15GF the specification is different I believe again it is just the finish but it is completely interchangeable with a 1097.

If you used BACR15BB rivet allowables you need to go back and reduce your numbers.