One of industry's oldest metalworking arts, has seen many changes in recent years. New and improved forging tools and machines have been introduced. Better forging metals have been developed. New alloys and new metals have been adapted to industrial needs through the skill of forging engineers and technical experts.
But our long experience in forging shows that many of today's most common difficulties and limitations are due, just as they were a quarter century ago, to improper or inadequate lubrication of forging dies or tooling.
In the past, various special "lubricating" concoctions having a base such as salt, soda, soap, or other materials, possibly in solution with water, were thrown,
slopped, or sprayed into die cavities. The most common practice was to swab oil or grease or mixtures on dies or tools. In some forge shops, the resulting smoke and fumes were almost unbearable.
Metal was being forced over a fluid film which, at best, was certainly a variable factor. In forgings with projections such as a boss, metal was supposed to fill even though it had to compress oil or gaseous films almost like a diesel engine- and the metal released largely because it was exploded off the tool or out of the die cavity.
Under these conditions forgings of desirable quality were the exception rather than the rule. The number of forgings produced per month was not what it should have been, and tool and die life was unnecessarily short.
Skilled operators cling to these old, established practices partly because, for many years, there were no real advances in forging lubricants and lubricating methods.
Our work, for over 50 years, has been the development and manufacture of special lubricants and release agents for improved forging operations. Our pioneering in this field led to the development of modern Renite forging lubricants and practical manual and automatic means of applying them.
Whenever metal moves against metal there is wear, unless a suitable lubricant prevents it. Many customers who operated for years with no lubricants have found that in die and tool life alone, the proper use of Renite saves much more than its cost. They have found that they now make much better, more uniform forgings, because the flow and release of metal can be so much more uniformly controlled over a properly lubricated surface. Today, of course, all forging operations can be made better, more uniform, faster, and more economical with the proper lubricant correctly applied.
There is an important difference between Renite and ordinary lubricants, which simply apply a wet fluid, waxy or greasy coating to tool and die surfaces. Renite dries instantly on die surfaces, "plating" them with a completely dry, uniformly thin layer of lubricant that will not flow, puddle or compress. Dried Renite is readily missable in water and will not adversely clog spray nozzle orifices.
Many different kinds of Renite are now used in forging operations, and new Renite formulas are developed as rapidly as new requirements arise.
Renite Forging Lubricants are pourable concentrates designed for dilution with 5 to 30 parts of clean city drinking water. They are perfectly stable as concentrates and will not cause settling trouble in Renite spray equipment when diluted with water. They have been formulated without corrosive or otherwise harmful additives, thus differing greatly from certain solid lubricant concoctions of somewhat similar appearance. Renite is a semicolloidal dispersion. It is easily diluted with "hard" tap water which is not always possible with many dispersions.
Renite must be SPRAYED AGAINST EVERY PORTION OF ALL TOOL OR DIE SURFACES OVER WHICH METAL IS WORKED EACH TIME A FORGING IS MADE. The atomized Renite will plate the surface of the tool or die and dry thereon instantly. Renite will not lubricate while wet. The surface temperature of the tool or die dries the Renite, forming the proper Renite plating. When tool and die surface temperatures are properly controlled, if only for the fraction of a second during which the Renite contacts the metal, this Renite plating is maintained. You can then forge to much more uniform contours, tolerances or concentricity's than is possible by any other means. In nearly all forging operations metal will fill much better, then release without sticking and without being exploded out of the die cavity or off the punch, assuring much better tool and die life.
oily film, getting smoke, fumes, explosions, etc.
Renite is entirely different, in both application and performance. It will dry instantly on any part of punches or dies against which it is sprayed. We have developed special manual and automatic atomizer and spray equipment with which every desired part of punches or dies is correctly plated with instant drying Renite lubricant either automatically, semiautomatically or manually.
Tool or die surface temperatures must be low enough so that the Renite and water mixture will wet the surface for at least a thousandth of a second and hot enough so that it will not stay wet or puddle but will dry instantly on the surface. We usually suggest a range of 300"F (149 degrees C) to 750"F (399"C) or preferably 400"F (204"C) to 550"F (288"C). It is interesting to point out that although Renite is a water based product it can produce a plating well above the boiling point of water. (Where chemistry of metals forged or other reasons require much higher temperatures we use a different series of Renite.)
When Renite, like S-26, is correctly sprayed against die surfaces visible to the operator, he will see a dull, gray black color. This will become a black, shiny polish as soon as the forging is made. Then the die surface is again sprayed with Renite and it again becomes a dull gray-black color (no longer black and shiny) until the next forging is made, when it again takes on a black, shiny polish.
This surface gives excellent lubrication, but is a dry, non wet, non oily surface that can be varied to control metal flow. It is the dry Renite plating, not a wet film of Renite solution, that provides lubrication without frictional wear and without smoke, fire or explosions which can crack and destroy die surfaces. Unlike some other concoctions (which are corrosive) Renite is absolutely noncorrosive to dies, tools and forgings. As a result, smoother forgings (free of oxidative corrosion) make savings possible in later stages of manufacture.
We start by using a Renite hand spray gun, with tubes just long enough to enable the operator to reach all die surfaces without getting his hand under the die block. The Renite atomizer on this spray gun permits quantities sprayed on the top and bottom dies to be adjusted independently, and by changing nozzles we can get almost any pattern on either die. Many operators are quick to acquire skill and speed in handling tongs with one hand as they use the Renite hand spray gun with the other. This system has been used successfully for many years in forge shops.
We have also developed automatic Moto-Spray units which apply Renite uniformly to die surfaces to meet special needs involving speed of operation, long runs, or even frequent job changes during the day. A special bulletin describing Moto-Spray is available.
In applying Renite, Moto-Spray "reaches" into parted dies, sprays in a preadjusted pattern that covers even the most irregular cavities in the most effective manner, and returns to starting position as fast or slow as the job requires.
Stroke is infinitely adjustable to fit any need. You can have any number of atomizers (from 1 to 7) in any position or combination of positions and with various spray nozzles, providing a spray of just about any pattern, volume, duration, density and travel you could call for. Moto-spray will automatically operate through its complete cycle by pushing or hitting the palm actuating valve, or by tripping a cam valve mounted on your machine, or electrically by means of a micro switch, solenoid valve or similar actuating device.
In some plants the Moto-Spray is mounted horizontally at the side of the press so that it will come in the window and will be so adjusted to spray only the top and bottom die cavity of the finisher die; or of the finisher and blocker; or of the finisher, blocker and buster; or of the finisher, blocker and finisher, as the case may be.
In other cases the Moto-Spray is mounted at the window on the side of the press upside down and suspended from above to operate in much the same manner. in still other instances, the Moto-Spray is mounted behind the press or opposite the operator. In a few cases it is even mounted alongside the operator so that it moves in and sprays one cavity, or sometimes it is fitted with two or more atomizers so it will spray more than one die cavity at the same time. Moto-Spray can be actuated manually or interlocked automatically with the forging press.
On forging machines we frequently have the problem of gathering stock or otherwise working metal in a die cavity which must be lubricated in the same manner as a die cavity on a forging press or a tool on an upsetter. If we are merely gathering stock in one die cavity at the top of the die block we can frequently mount stationary atomizers above the opposite die block and spray this cavity.
However, if we are working metal in two or three different die cavities as we progress downward in the upsetter, they cannot be properly sprayed by stationary atomizers mounted above or outside the die block. In such cases we mount a Moto-Spray above the die block, in position to move downward automatically, spraying the opposite die cavities as it passes them until it reaches the desired point where it automatically reverses, spraying the die cavities again as it comes out, if necessary.
In some cases, we have positioned Moto-Sprays with specially designed atomizers that automatically spray die cavity surfaces and noses of the punches while they move downward. A very flexible arrangement of atomizers and Moto-Sprays has been developed to meet most conditions on almost every type and size of upsetter, press, impactor, roll or hammer making almost every type of forging. When proper Renite and water mixture is used and die temperature controls put into effect, it is possible to establish and maintain a Renite plating on all surfaces of the tools and dies. Better forgings can then be produced with much more uniform concentricity's, contours or tolerances and you get much better tool and die life.
On forging hammers we have the same general situation as for forging presses and upsetters-- proper surface temperatures must be maintained at the time Renite is applied. A simple, stationary (automatic or manual) spray system has been developed for this purpose.
There may be special cases where metal is extruded or caused to flow for so great a length over a portion of a tool or die surface that the Renite plating is worn off, and galling might develop. This type of operation requires special consultation. However, in almost all forging operations, Renite can be properly applied, and this has enabled many customers to improve their forgings and greatly increase tool and die life. In almost all of the few cases where Renite has been reported to be unsatisfactory on first attempts to use it, we have found that it was due to overlooking one or more of the basic and simple rules mentioned above. Just spraying or fogging Renite in the general direction of tools or dies is of no value. It must be sprayed against all surfaces of the die. Frequently in spraying a blind cavity, an operator thinks he has sprayed Renite against all surfaces, but has not done so. The greatest difficulty customers have had in their first use of Renite has been due to faulty application or the lack of correct temperature control of sprayed surfaces. Lubricants are available for warm and cold forging. Graphite free products are supplied for special applications. A relatively smokeless graphite/synthetic oil product is available for situations where temperatures or die configurations are not suitable for graphite/water products.
Nearly all types of forgings have been successfully made and often greatly improved with the aid of Renite. This success ranges from hand spraying Renite in small job shops where job changes are frequent to the world's highest speed automated forging operations.
Forging is an old industry or art. Old, established habits often prevail. What we propose may seem just as new and different to some operators as the first airplane flight to someone who has never been off the ground before. Adjustment to a new feeling and experience is necessary, but the results are worth the effort, many times over.
Renite lubrication engineers will be glad to give you complete information on Renite and its application by manual or automatic atomizing and spray devices to your specific needs for better, faster production with less die wear.
Please tell us:
- What kind and size forging or extrusion equipment
- What metals are forged or extruded
- General type and size of forgings or extrusions
- Surface temperatures of dies and tools
To HOME PAGE