radius in slotted holes

Date 10-25-2010 15:59

A slotted hole for bolting would automatically be 1/2 the diameter of the said called out slot/bolt size. 15/16" slotted hole for a 7/8" bolt would be a 15/32" radius on the ends.

I don't believe, to my limited mental recollection, that either document or the RCSC Bolting Section of AISC Manual calls out the radius. They only give the hole size tolerances for bolts in the application being considered.

NO, it is not considered a re-entrant corner.

Have a Great Day, Brent

By strat

Date 10-25-2010 16:25

Thanks Brent, I didnt think it would be considered a re-entrant but i could not find anywhere that stated the radius for a slotted hole, I didnt know if that would apply, our machine shop guru machined some 3/4 plates with 1 1/6 by 2 1/2 slotted holes but did not radius them, just a very small radius at the four corners, told him that wouldnt fly, hurt his feelings, he went straight to the prez. I got overrided

Thanks Brent
Strat

By 803056

Date 10-25-2010 19:59

D1.1 addresses the radius of a slotted hole that will be welded, but not for a bolted connections.

Best regards - Al

By strat

Date 10-25-2010 20:45

Thanks guys,
Brent, or any one know that its stated somewhere as to what Brent said, 1/2 the dia. of the said called out slot/bolt size, like i said, im dealing with the man that knows all(the machinest)
Strat

By welderbrent (*****)

Date 10-25-2010 22:38

Strat,

I will look and see if I can find something 'in print', BUT, it is just an extended hole. A 15/16" X 1 1/2" slot is just 2> 15/16" holes with an extension in between. At least when used for a bolted connection (measurements just for example, may not be actual slotted hole dimensions). Thus, at the ends, the radius would be 1/2 of the diameter or... 15/32". Any hole/slot I have ever seen called out for bolting was just that, a 'hole' extended by distance. And all my punches are designed that way. I have many punches for different size slots and all are radiused per the width of the slot/diameter of the hole.

Now, as Al stated, when being used for a slot for welding, you may change those features. Then both D1.1 and AISC have specific qualifications for the slot dimensions for welding. Again, I would have to spend some time looking as they are not on the tip of my fingers, tongue, mind.

Unless someone beats me to it, I will try to get you some numbers a little later.

Have a Great Day, Brent

By welderbrent (*****)

Date 10-25-2010 23:39

Okay, look at D1.1, Clause 2.3.4.1 & .2. Without taking the time to quote them, if you have a slot to be welded in with a fillet weld in 1/2" material, the slot would need to be at least 13/16" in width. The slot ends will need to be semicircular OR shall have the corners radiused not less than the thickness of the part in which it is made. In our previous example that would mean EITHER a radius as previously mentioned being 1/2 the diameter of the width/hole equalling 13/32" OR 1/2" to be at least the thichness of the material it was made in. Thus, if a wider slot were called out for welding in order to get the proper total effective length of weld required, say 1 1/2" wide slot, then the radius for the corners would have to be at least 1/2" to match the base material thickness.

Look all the way through 2.3.4. Quite a bit of info as to dimensions for slots for welding.

Now, I'll take more time and look through AISC for the bolting criteria for slotted holes and see what I can find.

Have a Great Day, Brent

By strat

Date 10-26-2010 00:25

Thanks Brent,
greatly appreciated
Strat