Drilling for dollars

Discussion in 'Civil Related Discussions' started by Wireless Estimator, Feb 1, 2008.

  1. Wireless Estimator

    Wireless Estimator Administrator Staff Member

    Some specifications call for the contractor to drill stitch bolt and other attachment points on the existing structure for bracing additions. Do not assume that it can be done with a hand drill. Some applications require specialized equipment such as annular drills and multiple, expensive drill bits.
  2. Chas  Wagner

    Chas Wagner Industry Observer

    A good example of such is when larger leg connection bolts must be added. Many contractors plan on using standard drilling devices and are overwhelmed when they proceed with the activity. One factor that seems to be overlooked the most is being able to get the proper equipment and the work required to get access to the inner most connection bolt [between the end connections of horizontal to leg] such relocating coax temporarily or having a device that will allow working from above the connection plate and provide enough depth to reach the flanges. Also using a device that has enough travel depth to bore all the way through thicker flanges.

    There are several manufacturers to choose from. Also I suggest "annular cutters" for some applications and "bridge-reams" for others. It will be difficult to buy one tool to do it all.
    Get friendly with a knowledgeable tool distributor.

    Chas Wagner
    Project Manager
    Certified Welding Inspector
    Tower Field Services Group
    Morrison Hershfield Corporation
    404 / 787 - 6237 Mobile
    734 / 293 - 8901 Efax

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