Slotted hole tolerances

By SWN1158 (***)

Date 03-02-2021 11:41

With regard to how far slotted holes can be from the correct dimension, it depends on what these holes are bolting to.

With regard to clip angles that have 13/16'' x 1'' slotted holes and the center to center of slots are suppose to be 5 1/2''... these slots are for 3/4" bolts, and they have 1/4" "play" in a 1" long slot. So for something that has a 5 1/2" c/c dimension, the actual c/c dimension can be 5 1/4" to 5 3/4" and still work.

By ididntdoit89 (*)

Date 03-02-2021 12:10

Thank you for this information. Where can i find this in a code or standard?

By SWN1158 (***)

Date 03-02-2021 17:39

My responses come from 44 years in the structural steel fabrication business.

By 803056

Date 03-02-2021 17:59 Edited 03-02-2021 18:02

I was under the impression the tolerance from the specified location (center) was +/- 1/16-inch regardless of whether it is a standard hole, oversized hole, or slotted hole.

I understand the holes can be used even if the tolerance is exceeded as per your example, but that isn't the reason to use slotted holes.

AISC has published two manuals, one for the detailer and a separate manual for the designer. Since I'm not in my office, I can't quote the exact titles or the page number where the information is found. Sorry.

Just saying - Al

By SWN1158 (***)

Date 03-03-2021 11:08

As far as I know, hole tolerances are not addressed. This was a related question and answer from AISC's Steel Solutions Center...

3.3. Element Location Tolerances

3.3.1. IS A TOLERANCE ON HOLE OR HOLE PATTERN LOCATION SPECIFIED IN THE AISC CODE OF STANDARD PRACTICE?

No. Neither the ±1∕16-in. tolerance, where applicable, on overall length of members framed to other steel parts nor the 1∕16-in. clearance on size of standard holes should be construed as implying that the tolerance of ±1∕16 in. also applies either to the maximum tolerance on hole location within a pattern of holes or to the position of intermediate connections.

Table J3.3 in the AISC Manual lists maximum dimensions of standard, oversized, short-slotted and long-slotted holes, which is based on the RCSC Specification.

With regard to the use of slotted holes or oversize holes, I take advantage of where the AISC allows them, simply because it gives a little more tolerance during fit-up in the shop, and their use helps during the erection process. In some cases, it eliminates the need for drift pins.