proof stress of 10-32 bolt 1

[LCform]

Hi All

I want to calculate the preload of the 10-32 high strength bolt, for which I should put in the formula , the tensile shear area of the bolt , the proof strength of the bolt , and the coefficient.

just wanted to know if I have found the right numbers : 0.02 for the area , 85000 ksi for the proof strength(stress) and 0.89 for when it's not gonna re open. so it's 1513 lbs , is this a reasonable quantity ?

 

[CoryPad]

Stress area is 0.02 in², proof stress is 85 000 psi for Grade 5, and I have no idea what you mean by 0.89 and re open force (or mass?) of 1 513 lbs.

 

[LCform]

About the constant there was some page in the website that I used it yesterday and now I dont find it , but it says that if the bolt is supposed to reopen and close in the future, the constant should be 0.75 , otherwise 0.89

Link

 

[desertfox]

Hi

If you want to reuse the bolt or screw you tighten it to 75% of the yield stress value, converse if the bolt is never to be reused you go to 89% of yield stress for bolt tightening, so that explains the .79 and .89 values.

“Do not worry about your problems with mathematics, I assure you mine are far greater.” Albert Einstein

 

[Tmoose]

Table 26 on page 32 here -

http://www.holo-krome.com/pdf/Consolidated_Tech_Manual.pdf

Says to tighten a 10 fine thread SHCS to 90 in-lbs which will stress the screw to about 75% yield, and achieve about 2100 lbs clamp load.

There is about 1/2 page of conditional notes for that table.

How much clamping do you need?

 

[LCform]

Thank you very much , well since my design is not directly dealing with the bolt, and bolt load , I was not told about that , so I had to guess something, I could also use rigid conditions instead of real bolt load, but maybe I will try my design with both 1513 and 2100 to see how much does it affect my analysis

 

[Tmoose]

Is this analysis for a product that may be built in the future, OR a search for the solution of problems with actual parts in testing or service?

 

[LCform]

It's an optimization of a design , but it's not in service, but after optimization will be

 

[zeusfaber]

Watch your units. 85000 ksi is unreasonable by several orders of magnitude.

A.

 

[tbuelna]

Where can I get me some of that 85,000ksi UTS fastener material?

 

[LCform]

You are right , 85 ksi =85000 psi it was ,thank you