Tuesday, December 2, 2014

F1554 Bolts Have Become An Industry Standard

By Ida Dorsey


You will need the right equipment for any project you undertake. The ASTM F1554 is an anchor bolt that can take the form of being bent or headed. The headed bolts are non threaded and have a forged hex, square headed or a heavy hex head. The tip is rooted into the concrete foundation where it will lock any steel columns, bridge rail or light poles firmly in place.

There are three different grades, the 36, 55 and the 105 and they are all designate the minimum ksi or kilopounds per square inch of the anchor bolt. These can be roll threaded or cut and the 55 grade can be changed for the 36 grade if needed. Each one comes with a specific colour code at the end so that identification in the field is much easier. The 36 bolt is blue while the 55 is yellow and the 105 is red.

The grading of the 36 is that it has low carbon with a ksi yield steel anchor. The 55 has a high strength capacity with low alloy and the 105 is heat treated and of alloy, also with high strength capacity. Supplementary testing will only be done when specifically asked when purchased.

For all marine projects these bolts need to be hot dipped in galvanised or stainless steel. This helps to prevent corrosion and ensures that their strength is intact. Stainless steel in also known as inox steel and has some chromium content added. It does not generally stain with water but this can happen in low oxygen, poor air circulation and high salinity areas.

There are even bolts that are dipped in galvanised steel. This means that the steel or iron has gone through a chemical procedure that will help prevent it from rusting. The steel will be coated in a few layers of zinc as rust cannot damage this kind of defensive metal. The general purpose of this is that excess zinc will be left in the threads thus helping to prevent the nut from threading onto the fastener.

Rust or iron oxide helps to speed up corrosion by making more iron oxide. As this happens the outer edges of the exposed steel will flake and fall away leaving a much weaker structure behind. Chromium will form a covering which helps to prevent the spread into the inner structure.

Galvanising is a way of applying a zinc coating to the steel, aluminium or iron as a means of preventing rust from happening. The commonly used method is hot dip where they are immersed in a bath of molten zinc. The temperature will be as high as 460 degrees Celsius and when they are exposed to the air the zinc will respond to the oxygen. It will then form a zinc oxide which will further react with the carbon dioxide where it will form zinc carbonate.

Unfortunately the grade 55 thread rods are not easy to find but they can be made to order. Many people that use these bolts are keen to look up the specifications and these are available on PDF through the Portland Bolt Manufacturing company. They even have a live chat facility available so that all questions regarding fasteners and bolts can be answered immediately.




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