Slip Critical Connections vs Bearing Type
Slip Critical Connections vs Bearing Type
(OP)
Consider a standard hole 3/4 inch diameter A325 bolt in shear.
Allowable stress for bearing type (N) connection is 9.3 Kips, and for slip critical (F) connection is 7.7 Kips
Slip Critical connection are required to be inspected in the field for correct tension with torque testing devicess, or with Direct Tension Indicators, etc., while the bearing type is not required to be inspected.
So how come the N connection which doesnt have to be checked gets a larger allowable stress then the Slip Critical connection which is inspected.
I would think that something which does not require inspection would get a lower allowable stress.
Allowable stress for bearing type (N) connection is 9.3 Kips, and for slip critical (F) connection is 7.7 Kips
Slip Critical connection are required to be inspected in the field for correct tension with torque testing devicess, or with Direct Tension Indicators, etc., while the bearing type is not required to be inspected.
So how come the N connection which doesnt have to be checked gets a larger allowable stress then the Slip Critical connection which is inspected.
I would think that something which does not require inspection would get a lower allowable stress.






RE: Slip Critical Connections vs Bearing Type
RE: Slip Critical Connections vs Bearing Type
RE: Slip Critical Connections vs Bearing Type
The slip critical connection limit state is slippage, not bolt failure. So the load is lower because after torqing, the load that causes slip is lower than the load that causes bolt failure.
The difference between the N bolt and the slip critical is not that great as the N bolt has a further penalty in that threads are not excluded from the shear plane as is the case with the X bolts.
RE: Slip Critical Connections vs Bearing Type
RE: Slip Critical Connections vs Bearing Type
if you are interested
http://www.boltcouncil.org/download/RCSC%20Specificatio...
see section 5