November 2021 Volume 3

MAINTENANCE

Maintenance Tips and Troubleshooting Forging Hammers By Jeff Fredline

Forging hammers have been used in manufacturing for over 100 years. They are a highly effective forging machine and continue to be used in many operations today. It has been said “Forging hammers are self-destructive pieces of equipment”. The knowledge base within the forging community regarding proper maintenance and operation continues to diminish due to the retirement of those with a wealth of experience and information. In this article we will attempt to review many of the important principles regarding forging hammer operation and maintaining your Hammer equipment in the best possible condition. Hammer Base The hammer base or anvil is the main building block for the hammer assembly. Due to the extreme forces generated against the hammer base, it is critical that it be mounted properly. When you install a hammer base there must be a foundation developed to minimize the shock transfer from the operational forces. There are a couple of well-known companies that can provide engineered foundations to support the dynamic load of the hammer; vibro-dynamics and gerb. Many hammers in the U.S. are mounted on a foundation of railroad style timbers assembled in a log cabin arrangement upon which the hammer base or anvil this then placed and then back filled. With each stroke of the hammer it bounces on the foundation which helps to minimize the shock transfer. The top surfaces of the hammer base are subject to extreme forces. One of the common areas of wear and damage is the pocket for the sow block. The sow block should be held tightly in the sow pocket with the wedge assemblies. If the sow block becomes loose in the pocket, it begins to move during operation and this continuous movement will eventually lead to wear and breakage in the base itself. Some hammers have a chevron style pocket and others just have a tapered side for a wedge. Between the sow block and the hammer base there is a sow key that assists in holding the sow block on location. If the sow block shows movement during operation,

the key and mating keyways will wear excessively. Part of proper maintenance is to properly hand fit the sow and sow key to the block as well as the wedge. You should maintain at 80% metal to metal contact as part of your fitting process. Important Maintenance Tip: Forging hammers run in a hostile environment. Running surfaces are exposed to metal flakes, slag, dirt and all types of contamination. Keep your hammer components as clean as possible, especially during the assembly and fitting processes. Any contamination between machined surfaces will lead to premature failure. In addition to the sow pocket, the column seats and wedge surfaces also are subject to the same wear and damage conditions. Important Maintenance Tip: Anytime there is excessive movement in a hammer component, a work order should be issued and the situation corrected as soon as possible. The longer you continue to run the hammer in a loose condition, the more severe the damage will be. Hammer Columns LH and RH (Side Frames) Proper alignment and mounting of the hammer columns are one of the most important elements of the proper function of the hammer assembly. There are several characteristics that must be maintained. 1. Overall height a. The LH and RH hammer columns must be maintained at the same height within less than .005” overall height. b. If the hammer columns are not the same height it will throw the centerline of operation off. In extreme conditions it will cause severe wear and tool damage. 2. Proper fit with hammer base a. There are (three) critical fits, (two) front to back and (one) left to right.

FIA MAGAZINE | NOVEMBER 2021 24