|
thermally cut bolt holes
thermally cut bolt holes shall be permitted if approved by the eor.
reference "specification for structural joints using astm a325 or a490 bolts, june 23, 2000 research council on structural connections section 3.3"
is there any concern to be aware of with thermally cut bolt holes?
will the holes be cut in the field? if so, my concern is that the person using the torch often is not interested in making the proper sized hole and that the edge is often jagged. if the hole is sized properly and the edge of the hole is clean and smooth, there should not be a problem.
this is a request for shop fabrication. i will not allow thermally cut holes in the field.
further the spec requires all holes for cyclically loaded joints to be ground smooth. this is not required for statically loaded joints. when holes exceed the specified tolerances, they must be treated as the next larger size which i interprept as adding additional or larger bolts.
i've heard another concern is that the thermal cutting alters the material properties of the steel. any validity in that?
rholder98
you are correct concerning the material properties change.
i looked through some of my resources and there's a great summary of flame cutting under the introduction section of one of our vendors at
there is some information about acceptable methods of creating holes at the aisc website (
please note that when we're mentioning cracks in thermally altered steel, we're not usually talking about something visible to the human eye. i've often had the notion that "i've been doing this for years and never seen any cracking" pointed out to me. so with a little patience i explain the cracks begin as micro-cracks and in some cases propagate to larger problems later on in service. that said i mainly work with cyclic joints rather than static loaded joints.
regards,
qshake
eng-tips forums:real solutions for real problems really quick. |
|