Thermally Cut Bolt Holes
Thermally Cut Bolt Holes
(OP)
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?
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?






RE: Thermally Cut Bolt Holes
RE: Thermally Cut Bolt Holes
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.
RE: Thermally Cut Bolt Holes
RE: Thermally Cut Bolt Holes
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 http://www.torchcutter.com
Summary:
Mild Carbon steels- some hardening around the local area but no significant detrimental changes.
Mid to High Carbon Steels - Hardening and potential cracking. Can be moderated with proper procedures.
The fabricators we use for our steel work can flame cut a hole so smooth its hard to tell if they cut it or drilled it.
I agree that hand torching bolt holes is bad Karma.
RE: Thermally Cut Bolt Holes
5.1.3. Does flame-cutting of bolt holes affect connection strength and performance?
Generally, no. Iwankiw and Schlafly (1982) investigated the performance of double-lap joints with holes made by punching, punching with burrs removed, sub-punching and reaming, drilling, flame-cutting, and flame-cutting and reaming. The comparison of 18 samples using 1/2-in. thick ASTM A36 steel plates with standard holes indicated that there is no significant variation in connection strength according to the method of hole formation under static load. Additional considerations may be warranted for much thicker plates, steel grades other than those tested, and Cyclically Loaded Structures.
Iwankiw, N.R. and T.J. Schlafly, 1982, “Effect of Hole-Making on the Strength of Double Lap Joints,” Engineering Journal, Vol. 19, No. 3, (3rd Qtr.), AISC, Chicago, IL.
last modified 23 August 2002
RE: Thermally Cut Bolt Holes
Regards,

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