×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Bolt holes do not line up exactly d

Bolt holes do not line up exactly d

Bolt holes do not line up exactly d

(OP)
Bolt holes do not line up exactly during erection and contractor is sometimes just enlarging the hole to be able to insert a bolt. They do not weld closed the unnecessary part of the hole, so you see a bolt in a large hole - they use a correct size of the washer of course and the bolt head is supported by the structural steel from three sides (only one side falls resting on the washer only). Is this a point of concern?

RE: Bolt holes do not line up exactly d

Yes, it can be. Depends on which direction is enlarged, and to a lesser degree how the enlargement is made.

RE: Bolt holes do not line up exactly d

(OP)
Hokie66, thanks for your answer. Could you elaborate more on the direction please?

RE: Bolt holes do not line up exactly d

If the bolts are in bearing, you don't want the bearing surfaces compromised.

RE: Bolt holes do not line up exactly d

(OP)
Ok. Thanks Hokie

RE: Bolt holes do not line up exactly d

There are limitations on what is acceptable for reaming. As noted the direction of the adjustment and the type of connection can an issue. AISC (Is this an AISC project?) does not provide information for holes greater than given in RCSC. A tolerance of 1/32 is allowed. If the hole exceeds the maximum hole dimensions specified then it may be necessary to increase the bolt diameter accordingly.

If the erector is using a torch to modify the hole sizes, you can have many more problems.

www.FerrellEngineering.com
Providing fabrication and erection efficient structural design of connections. Consulting services for structural welding and bolting.

RE: Bolt holes do not line up exactly d

(OP)
Connectegr, thanks. They are using a finger grinder for this purpose and this is basically ordinary carbon steel structure. The subject members aren't heavily loaded ones. This is not an AISC job. Which standard is the best to be consulted on this issue? What is RCSC?

RE: Bolt holes do not line up exactly d

RCSC - Research Council on Structural Connections - develops the specification for structural bolting. You can download the specification at www.boltcouncil.org

Some information about field modifications of bolted connection can be found on the AISC website or in AISC's Engineering and Quality Criteria for Steel Structures.

www.FerrellEngineering.com
Providing fabrication and erection efficient structural design of connections. Consulting services for structural welding and bolting.

RE: Bolt holes do not line up exactly d

i'd be concerned about opening a hole towards an edge.

FWIW, i wouldn't fill the hole with weld filler; i'd be more worried about the hole finish.

RE: Bolt holes do not line up exactly d

Yeah, I'd watch the edge distance too. It's always a good idea to provide extra edge distance above the minimum so this doesn't become a problem. If they have to enlarge the hole a reasonable amount, you can repair it by making a plate washer with the right sized hold and welding that onto the original structure.

RE: Bolt holes do not line up exactly d

(OP)
rb1957 and TLHS thanks for your valuable comments. Connectegr, thanks - I'll check out that website.

RE: Bolt holes do not line up exactly d

Structural steel, hmmm!! Here is one story about structural steel. Our company fabricated a tub girder with a sweep to specs, however, the designer contracted by the State used a program spitting out data which under-designed the tub girder. This information was not known at the time. This tub girder was all pre-assembled at our fabrication plant with no problem but when field erected, it rotated too much and to align the joints with the splice plates, the iron workers had to enlarge several holes. The State load tested the finished product( an "on ramp" to a major highway) OK, however, the life span of this ramp was diminished by about 40%.
So test your finish product before having it used by the owner and think about reducing its loading and life span.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources