Historic Structures

Tool Making Process Warwood Tool Company, Wheeling West Virginia

Raw materials arrive at southern end of plant and are stored there until needed. Primarily plain high carbon C-1060 steel rectangular and square bars and round rods are used for tools. Silicon-Manganese 9260 alloy steel is used for making certain types of tools. (The classification of steel is based on the carbon content and other alloying elements. For example, C- 1060 steel is 0.55% to 0.65% carbon, and 0.60 to 0.90 manganese. 9260 alloy steel is also 0.56% to 0.64% carbon, and also contains 1.80% to 2.20% silicon (silicon is the major ingredient for the deeper hardenability of alloy tools) and 0.75% to 1.0% manganese which give the steel special qualities. In this case, 9260 alloy steel attains a greater depth of heat treatment.) Steel is unloaded from trucks on the east side of the building by a crane. The crane loads the steel into bins in the center of the floor. From here the steel bars and rods are conveyed to the shears by a set of rollers. Typically, the steel bars and rods arrive in twenty to thirty foot lengths.

Steel stock is sheared to proper length with allowances for forging operations. The sheared steel stock is loaded into tote boxes for transit to other points in the forge shop.

The steel stock is heated in a furnace to 2,000 degrees Fahrenheit or forging temperature prior to forging operations. The furnaces are fired by natural gas and vary in size with some having only a single bay while others have two or three bays. All furnaces are of the slotted type design.

Warwood Tool uses four basic forges for its various forging operations as follows:

The upsetter is a hydraulic press used to hot forge bulbs on the end of the steel stock where additional metal is needed for subsequent forging operations. Generally, the maximum forgeable upset is two to three times the diameter of the steel stock. This process is similar to the one used to head nails. Warwood uses a two inch Acme Upsetter.

Tilt hammers are a mechanical form of the blacksmith's hammer. Historically, the tilt hammer was used to drive slag from wrought iron blooms (elongated iron bars) and form iron plate. At Warwood the Bradley Tilt Hammers are used to form the ends of many types of tools. Tilt hammers were often water powered. The Bradley Tilt Hammers are driven by electric motors.

Drop hammers forge metal by using gravity. The weight of the hammer forms the metal. Drop hammers are of a very ancient origin. Steam hammers on the other hand, were developed in the early 1800s by Englishman James Nasymth. Kasmyth's hammers were steam operated and could be controlled very precisely. Warwood uses gravity drop or board hammers and have an electric motor powered roller to raise the hammer. Warwood hammers have wooden shafts (i.e. board hammers), which lessen the vibrations caused by the forging operations.

The drop and tilt hammers are used for two basic forging operations: rough and finish forging. The process of rough forging transforms the steel stock into the shape of the tool being made. This is usually a two pass process: the first is a breakdown pass and the second an impression pass. The rough shape is the result of the dies used in the forging operation. These dies are known as simple closed dies. The cavities of the dies are in the shape of the tool being made. The heated metal is deformed into the shape of the tool when the hammer drops. The lower die is fixed and the upper die moves. Finish forging shapes the rough piece into the final recognizable form. This is done with a series of passes, both with closed impression dies. The mattock and curved tools usually require this two stage forging operation. However, some forging operations do not require both of these stages, but rather use only the breakdown and impression passes. For example, the manufacture of sledge hammers is a single stage process. Forging of tools is important because it refines the steel by tightening the grain, distributing inclusions and other impurities throughout the steel and toughens the steel.

The bar roller reduces the diameter of bar stock through a series of decreasing roll grooves. Unlike the conventional rolling mill, these rolls only rotate through a short distance and then reverse. Steel bar diameters are reduced by offering the steel bar into these series of grooves, backing the roller off and repeating until the desired diameter is reached.

The trim press performs three operations at once. First, it is used to remove the flash or feathering which is extruded from between the dies used in drop forging. Secondly, it finish forges the eye in tools requiring handles. Lastly, it stamps the tool with the warnings about tool misuse, country of origin and the Warwood name. Typically, this operation immediately follows the drop forging operation, because the tool must still be at forging temperature.

Shot blasting of tools is required to remove scale build up on the tool in preparation for heat treating and painting. The tool is tumbled and bombarded with lead shot, which removes the scale. Scale is formed on the tools during the heating and forging operations.

The grinding of tools is to remove rough edges and smooth the surface of the tool. In addition, the tool is ground to reduce stresses within the tool body under impact. Grinding of bevels on tools must meet specifications set by the American National Standards Institute, Inc (A.N.S.I.) and the American Railway Engineering Association (A.R.E.A.).

Tools made of alloy steel are heat treated (heat treating is the changing of the physical properties of steel by heating and cooling operations) in an open box furnace. Heat treatment is affected by heating the tool face to 2,000 degrees Fahrenheit and then quenching or rapidly cooling it by immersion in water or molten lead. This fixes or freezes the steels hardness in a fixed range. High carbon steel tools are heat treated using the Ajax Induction Heat Treater. Tools are heat treated by passing an electric current through it, followed by quenching. This machine heat treats tools at a rate of one per minute or approximately 60 to 100 units per hour. The Ajax machine attains heat treatment to a depth of one quarter inch and the open box furnace, heat treatment to a depth of one-half inch. The Ajax Induction Heat Treater is an universal heat treating system but for convenience it is set up to heat treat plain carbon steel.

The tools are inspected for defects. The tools are first subjected to material hardness tests using two types of non-destructive testing: Rockwell and Brinell. The tool face is given a Rockwell "C" Hardness Test. In the Rockwell "C" test, a diamond penetrator with a 331 pound load impacts the tool face. The amount of penetration determines the materials hardness. If the penetration is too great then the steel is to soft and if the penetration is too shallow the steel is to hard. The Rockwell test is used on smooth flat surfaces. Tool sides are subjected to the Brinell Hardness Test. This test is similar to the Rockwell test, but the penetrator is 10,000 millimeter ball with a 3,000 kilogram load. Like the Rockwell test, the penetration determines the steels hardness. Railway Striking Tools, under current railway specifications, must have a hardness of 51-55 Rockwell "C". All other striking tools must have a hardness of 45-60 Rockwell "C" Picks, Mattocks, and bars call for a slightly lower hardness. If a tool fails the hardness test, it is rejected. If the tool passes, then it must be tested by magnetic particle inspection.

In magnetic particle testing, the tool is placed in a magnetic field, sprinkled with ferromagnetic powder and any imperfections or cracks will show up under a ultraviolet light.45 In most cases a random sample of tools is tested. However in the case, of railroad tools, every tool is tested. Each tool must meet A.R.E.A. specifications. However, tools such as wrecking bars or crow bars are not subjected to magnetic particle inspection, because these tools are not designed to be used as impact tools (like hammers).

Most tools will be painted Warwood Blue (a very dark shade of blue). Those tools made from alloys, however, are painted red. Garden tools, although not made of alloy steel, are also painted red. Some tools are not painted at all, such as current AREA Grade B Alloy striking and struck tools. Painting of tools is done with a conveyor system which dips the tool and then slowly conveys the tool until the paint has dried. There are three lines: one for red paint, one for blue paint and a hand dip line for either red or blue paint. Following painting, tools with faces, such as hammers, have the striking faces polished. Warwood uses a water based paint, but formerly used a lacquer based paint.

Handles are then attached if required. The handle is inserted in the tool, the wedge placed and set, and the waste wood sawed off. Hickory handles are used for hammers and picks, and ash handles are used for garden tools. Warwood also offers fiberglass handled striking tools.

Packaging of the tools and shipping are the final stages of the tool making process. Warwood tools are shipped to points across the globe, as well as the United States, Canada and Puerto Rico. Many track tools are sold to the major American and Canadian Railroads. Warwood Tool hopes to exploit the market created in Eastern Europe because of the recent political changes.

Warwood is equipped with its own machine shop. The shop makes and repairs dies. The dies wear quickly (after 10,000 units or between 30,000 and 40,000 blows) and need to be reground to bring them back into the correct tolerance. When the die can no longer be reground, then a new die has to be fabricated from a block of steel. The longevity of the dies depends on the product being forged and, particularly, the type of steel being used. The eight pound sledge hammer uses three or four sets of dies per year because it sells well. The sixteen pound sledge wears dies out on a rate of one set every four or five years, because sales are fewer. Alloy steel wears the dies more quickly, than does plain carbon steel. Machine shop tools at Warwood include lathes, planers, milling machines, and shapers.