Beware of Hidden Costs
Out sourcing work also means verifying the quality control required of the product to be created by the vendor.
The holes pictured above were installed and plates were cut to size by a reputable vendor. Most of the lot was rejected by quality control upon receipt to the shop. You might imagine the shock.
Though the vendor completed the work order within schedule, they sacrificed quality to do it.
The plates had to be replaced, which created a scheduling issue that was resolved by unplanned overtime.
It is suggested to schedule a QC visit to the plant prior to completion of the order to ensure project quality control requirements are met.
No fabricator needs these unpleasant surprises disrupting delivery schedules!
Don't let this happen to you!
Steel estimators work hard on every job to get it right. Some companies have the estimator also project manage the work that they sell. These people get a first hand look at the impact of unforeseen labor and material factors. Innocent mistakes can make for an expensive lesson.
Among common errors are the assumptions made regarding column base plates. The steel estimator lists the materials as they see them, plate thickness, width, length and quantity of holes, and material grade. Depending on the thickness and quantity of the column base plates, estimating may price the materials as purchased cut to size. If the shop has a burning machine, they may option for buying sheet stock and cutting it in the shop. If the plates are extra thick and heavy it may be decided to ship purchased materials to a vendor for special cutting. But isn't the estimator forgetting something?
Read through some contract specifications and we may find that the burning of holes is unacceptable. Base plates for columns may be required to be milled for flatness prior to fabrication. Often there is nothing specific mentioned about the column base plates in the specifications, so references for AISC compliance will govern.
The section for finishing of Column Base Plates in the AISC Code states that rolled steel bearing plates 2 inch thick or less is permitted without milling providing that satisfactory contact is maintained. Satisfactory contact involves the conditions as stated in ASTM A6 for flatness. The code also continues that plates 2 to 4 inches may be straightened by pressing, and if no presses are available, then they will need to be milled. Anything over 4 inches needs to be milled. Further, conditions where the columns are full penetration welded to the base plates milling is not required, nor is it necessary to perform milling of the underside of the base plates.
If milling is found to be required, the plates considered in the estimate will need to be listed as a thicker material to allow for the milling function. The purchased thickness is determined both by how much meat must be taken off at the milling process and what is available as the next closest available stock size.
The steel estimator must then add the cost of thicker materials, milling of the plates, plus additional shipping and labor for handling for materials used. If the work for plate milling is to be subcontracted out, consideration also might be given for the anchor bolt holes to be burned or bored at the same time.
While not all jobs will require this additional step in fabrication of the columns, it is important that the estimator is aware of such conditions for when the opportunity requires it. Not thinking this one through at the time of quote is what makes a low bid.
Steel Advice - June 2011
This manual is the guide for anyone wanting to know more about steel, steel fabrication and the steel estimating process. There is no other single publication offering a compilation of information of this type for the steel industry today.