Bearing Strength for Bolted Joints

Bolts are designed for bending, shear, tensile loads & not for Bearing strength. Since the bolts are having discontinuous surface (crests & troughs).

You have not specified the application, but still for that matter u can design special bolts having half length as a cylindar & remaining threaded or else un can use bolts for holding & provide some step in your design or some press fitted cylindrical pin for bearing load.

I agree with you.But my question was different.

Let me make it clear.

A bolted Joint Join 2-more components together.A a bolt is preloaded by Tightening to a specified torque,it produces compressive bearing pressures below Bolt Head.

I requested to provide any details if available for this allowable Compressive yield strength/Bearing pressure for the components getting clamped.

If this is not sufficient,parts getting clamped would yield, resulting in preload losses.

I feel now I have made my Question more clear.

Request to pls provide any emperical relation if atall exists between Allowable Bearing Pressure & UTS or Tensile Yield Strength for:

St44.2

16MnCr5

Al 6061T6 Brass Delrin

This site may help - http://www.matweb.com/

Sorry,

No info available on Allowable Bearing Pressure.

Any data from AISC or ASME??

Good Morning!

Try these:

http://euler9.tripod.com/fasteners/preload.html

http://www.turula.com/bolt.html

http://www.roymech.co.uk/Useful_Tables/Screws/Bolted_Joint.html

http://www.engineersedge.com/fastener_thread_menu.shtml

http://www.engineersedge.com/calculators/torque_calc.htm

http://www.fandisc.com/tti.htm

Start with the last one (fandisc) if that will work for you - it's the easiest.

Keep in mind that all of these have the potential to be innaccurate as they rely on friction coefficients that really need to be determined experimentally in situ rather that "guessed at".

I think you may be looking for the euler equation, which isolates 3 components of the force. You can use this in combination with matweb to get your material parameters to determine what you can get away with using these materials. Be mindful of the inherant innacuracy of this process - watch your safety factor(s).

Good Luck & have a nice day!

In general block shear will control for high tention bolts. You should investigate the material being bolted not the bolt itself. That is because the weakest bolt is made from A36 steel and there for has a tensile strentgh of 36 kips, 3600 lbs/in^2. We design the connection based on reactions find what the resultant forces are and add the minimum even number of bolts arranged in a semetric why to eliminate eccentriciy and if block sheer is a problem provide more space in between the bolts. The only thing left is to find what kind of steel you are using. No construction code defines strengh based on chemical composition even though that composition is related to strength.

Bolt strenth= .9 Ab Fy

(LRFD variable) (Ab area bolt) (Fy tensile strenght)

if the bolts are used in a slip critical stiuation ie excessive vibration change .9 to .65