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  1. ajh1

    Bolt Threads in a Shear Plane

    In a tapped bolted joint I believe you will always have threads in the shear plane. If you stop the threads below the shear plane (assuming the bolt head is at the top), then the shank of the bolt is in the shear plane (which is good), however you can't thread a shank into a hole that is...
  2. ajh1

    A325 Bolt Shear Strength

    AISC opted to ignore the change in tensile strength. If you compare to CSA S16 you will see they took the change into consideration. I think that AISC's rationale was that most of the A325 bolts actually showed 120 ksi regardless of the original requirements so they simplified the process. With...
  3. ajh1

    Reuse of TC bolts

    If the stem has been twisted off, I would say that you can't reuse them. If they've simply been put into a snug-tight only position, then you should be able to reuse them. The way to check is if you can thread the nut fully to the end of the threads by hand, then the bolt has not stretched due...
  4. ajh1

    2 bolt end plate connection design

    AISC Design Guide 16 does have a 2 bolt condition (flush end plate, bolts inside the flange) along with a 4 bolt condition (extended end plate, 2 bolts outside of flange, 2 bolts inside of flange). You might be able to work from those if what you have is a 2 bolt condition with the bolts...
  5. ajh1

    Weld symbols for hidden edges

    You don't indicate the size of Item 2. Are edges 2 and 3 actually accessible with a welding gun? The most straight-forward way to indicate the welds would be to take the cross-section, i.e., side view you have and show a single sided filled symbol pointing to each edge that you would like to be...
  6. ajh1

    Using double washers in structural applications?

    Keep in mind that RCSC requires a pre-installation test to confirm the turn-of-nut rules. Also, the turn-of-nut requirement may not be the same with a metric bolt as with an imperial measurement bolt, (different thread pitches, etc.). Again, a test per RCSC Section 7 would establish what is...
  7. ajh1

    Fatigue of MS Bolt in Shear

    AISC Table A-3.1 Item 2.3 is listed as "Base metal at the net section of other mechanically fastened joints except eye bars and pin plates. The illustration adds (Note: figures are for snug-tightened bolts, rivets, or other mechanical fasteners.) There is nothing in this listing that either...
  8. ajh1

    Bolt Torque Question

    Download the RCSC Specification, free at www.boltcouncil.org. Take a look at Section 7 on pre-installation testing. This is generally done with a Skidmore tension device. If you use a calibrated wrench in the test you can establish a specific torque to use to get to the tension you desire in...
  9. ajh1

    Shop Weld Oversized

    On your second example, you are correct, the weld should be viewed as a flare bevel due to the radius on the corner of the tube. The 5/16R value assumes that the weld is filled flat to the surface of the tube. It is permitted to use either less weld or more weld, but you will then need to...
  10. ajh1

    Shop Weld Oversized

    The limitation would be 3/4 - 1/16 = 11/16" max. The restriction is to insure that you can distinguish the edge of the weld from the edge of the plate. That said, you should be considering the strength of the tube wall where it attaches to the weld. A larger weld may not actually increase the...
  11. ajh1

    TORQUE VALUE ON GALVANIZED/BLUE FINISH A 325 BOLTS

    It depends upon the purpose of the torque. If the engineers are trying to mandate a pre-tensioned bolt, they need to specify a tension level, not a torque level, and you would need a pre-installation procedure to insure that you do in fact get the tension required with whatever torque you...
  12. ajh1

    TORQUE VALUE ON GALVANIZED/BLUE FINISH A 325 BOLTS

    Galvanized bolts are required to be lubricated for installation. The lubrication is going to affect the torque values as will any other surface condition effects. Depending upon the lubrication type used there could be a wide variety of results.
  13. ajh1

    TORQUE VALUE ON GALVANIZED/BLUE FINISH A 325 BOLTS

    Not sure exactly what your question is. Structural joints, assuming a requirement for pretensioned bolts, are based on a tension requirement. The only way to get the equivalent torque is by using a testing machine, generally a Skidmore, with a sample of the actual bolts being used. When the...
  14. ajh1

    Are US made A307 bolts hard to get?

    We used to use both A307 and A325 bolts in our projects and decided ultimately that the cost differential between the two was not large enough to justify stocking both varieties. Other than a speciality thin head bolt that is A307-type material we use strictly A325 bolts these days. In many...
  15. ajh1

    Welding Chinese Steel to Australian Steel

    The slightly higher sulfur content permitted in the Chinese steel may give some problems with welding if you are running a fast welding process, otherwise the two steels appear fairly equivalent. Keep in mind that while the standard permits certain upper bounds of each element it is unlikely...
  16. ajh1

    High strength bolts torque values

    RCSC provides the guidance in North America for bolt tensioning methods. Their spec can be downloaded for free from www.boltcouncil.org. The guidelines in AS4100 read very similarly. The two permitted methods that are listed are "part-turn" (equivalent to US turn-of-the-nut) and the use of a...
  17. ajh1

    Unique Connection Help

    Be very conscious of your torsional forces on the W27 beam. Without proper kickback bracing you are going to see rotation which tends to do ugly things to things out at the end of the cantilever. It doesn't take much rotation to create unacceptable deflections (sagging) of the supported sign...
  18. ajh1

    minimum weld size

    Minimum weld size is more generally controlled by the thickness of the material being joined. If you try to put too small of a weld on a thick plate, you don't get sufficient heat input to make the weld "stick" to the underlying material.
  19. ajh1

    HDG and dual cert A325/A490 bolts

    Given that the issue of hydrogen embrittlement is most related to bolt strength and hardness, it would seem that a dual certified bolt (never heard of such) would be required to meet the most stringent criteria of the various certifications, i.e., in this case the A490 and should therefore not...
  20. ajh1

    A490 Bolts and 90% Zinc Rich Primer.

    There is a coating called Dacromet that has now been approved by ASTM and RCSC for coating of A490 bolts. It's weathering characteristics are similar to hot-dip galvaninzing.

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