SHEAR AND BENDING STRENGTH OF AN BOLTS

[EDMO 1078]

Anyone know where to get the shear and bending strengths of AN bolts?

Need sizes from 1/4 to 5/8 diameter.

Wondering how they compare to Grade 8, 9 & 12.

I know that the costs are high because of the testing to certify them. Not concerned with cost - just strength.

ED in MO

Edited 25 May 2012 by Ed In Missouri

[birddog486 21]

I'm not sure of the strengths but I was reading an article recently saying the AN bolts are grade 10.9

I was thinking that hardness would make them brittle but??

Travis

Anyone know where to get the shear and bending strengths of AN bolts?

Need sizes from 1/4 to 5/8 diameter.

Wondering how they compare to Grade 8, 9 & 12.

I know that the costs are high because of the testing to certify them. Not concerned with cost - just strength.

ED in MO

[dholly 718]

See: p.19 Joint Design

FastenalTechnicalReferenceGuide.pdf

[EDMO 1078]

See: p.19 Joint Design

Thanks Doug, That gives me some ballpark figures - think it is in my Machinists Handbook too.

However, No answers on AN bolts in it. I know that is published somewhere. Not in AC43-13.

Will check my AMT books.

Havent used Fastenal since I left the government.

Last time I needed 6 Belleville washers: Fastenal would sell only a box of 50 for $518.00.

I got 6 from Grainger for $30.

ED in MO

[EDMO 1078]

I'm not sure of the strengths but I was reading an article recently saying the AN bolts are grade 10.9

I was thinking that hardness would make them brittle but??

Travis

The grade is based on the Alloy used, strength, and of course heat-treating, which can make them tougher and harder.

Usually, the optimum between toughness and hardness is where you want them to be. So, after quench hardening, they are reheated to a temperature which gives them that and makes them less brittle by "tempering".

ED in MO

Edited 25 May 2012 by Ed In Missouri

[John_L_Seagull 0]

If a steel alloy bolt is in shear, then you use 60% of tensile strength as your shear strength

http://www.mechanics...hToughness.html

Tensile Strength

http://www.mechanics...leStrength.html

Hydrogen Embrittlement

http://www.mechanics...rittlement.html

An interesting example of hydrogen embrittlement is the fatal accident of a Bell 206 helicopter in British Columbia in June of 2000. The screws in the fuel control unit broke due to hydrogen embrittlement. The repair facility replaced the screws during overhaul with standard AN503 screws. Ordinarily hydrogen embrittlement is not a problem with these screws because the rated tensile strength is 125,000 psi, well under the 145,000 psi where hydrogen embrittlement becomes a problem.

However, the screws tested much stronger than they should have been due to improper heat treatment. The cadmium plating applied to the screws then introduced hydrogen into the steel. If the screws had been manufactured to the proper tensile stress, they would not have failed and the fatal accident would not have occured. This accident was caused by screws that were stronger than they should have been. In fact, the entire lot of screws were non-conforming.

ref. Transportation Safety Board of Canada, Aviation Investigative Report, AW00W0105

http://www.mechanics...rittlement.html

Another interesting example of hydrogen embrittlement failure is when Lycoming changed their crankshaft gear retaining bolt to zinc plating from cadmium plating. This one bolt in the engine is a "Jesus" bolt, in that if it breaks, the engine quits. Unknown to Lycoming at the time, zinc coatings on high strength bolts with a hardness exceeding RC 39 have a history of hydrogen embrittlement failure. Soon afterward random bolt failures started to occur - a typical trade-mark of hydrogen embrittlement failure. Lycoming didn't heed the basic rule of aircraft design: "no single failure shall have a catastrophic effect."

General bolt and nut strength

http://www.mechanics...utStrength.html

Aircraft versus Industrial hardware

http://www.mechanicsupport.com/AircraftHardware.html

Last but not least...

A link.... to a whole lotta a other links

http://www.mechanics...m/Articles.html

Edit to fix broken link

[EDMO 1078]

If a steel alloy bolt is in shear, then you use 60% of tensile strength as your shear strength

http://www.mechanics...hToughness.html

Tensile Strength

http://www.mechanics...leStrength.html

Hydrogen Embrittlement

http://www.mechanics...rittlement.html

http://www.mechanics...rittlement.html

WOW - Now I can read, and read, and read. Maybe someday will know something!!!

Thanks, ED in MO

General bolt and nut strength

http://www.mechanics...utStrength.html

Aircraft versus Industrial hardware

http://www.mechanicsupport.com/AircraftHardware.html

Last but not least...

A link.... to a whole lotta a other links

http://www.mechanics...m/Articles.html

Edit to fix broken link