Oilite bearings and the Chrysler Amplex Division
Amplex was born to solve problems spotted by Carl Breer. The clutch of a car under development in 1927 would slip from the presence of engine oil, and grease or graphite could not be packed in without having the same problem. While GM made a bushing of compressed powdered copper and graphite, it tended to crumble when pressed into place.
An outside engineer named Sherwood “stopped by one day” to discuss ideas; Sherwood had patented the “cutless bushing,” a molded rubber, water-lubricated propeller shaft bearing for boats, which had grooves to allow lubrication by water. Sherwood suggested a new method, and Breer hired him and assigned Bill Caulkins, a research metallurgist, to work with him.
Together, the pair developed a process of compressing powdered copper (88.5%) and tin (10%) with some graphite (1.5%) in a die, then heat treating it in a furnace in the absence of oxygen with just enough heat for the tin to melt and bond the copper particles. The result was “astonishingly high in physical strength” and about 40% porous. The bearing was therefore then impregnated with oil, by putting it into a high vacuum, then filling the area with oil, and boosting the pressure to force the oil into the pores. When wiped clean, the bearings would show no oil; but increasing the temperature through friction brought the oil out. When the temperature dropped, the oil was re-absorbed.
Chrysler engineers developed bearings that were made of metal powders forced together under high pressure and heat (a process known as sintering). The ingredients were pure virgin copper (88.5%), tin (10%), and graphite (1.5%). The sintered bearings were so impregnated with oil — with around one third of their volume being oil — that, in most cases, they needed no service attention after installation, although they were seemingly solid.
The bearings were dubbed Oilite ®; Oilite bearings would be used in distributors, generators, starters, and ball joints as well as water pump and clutch pilots. Their first use in a car appears to have been in 1932.
Breer and his associates suggested to Walter P. Chrysler that he set up a new division which could sell products based on the discovery, as well as related parts. Thus was Amplex Corporation and its Oilite Division. Soon, the engineers developed other sintered metals using ferrous and non-ferrous materials, producing all types of bushings and gears.
One Amplex development was an oil impregnated bronze; it was a large pore metal material used in leaf springs and joints, able to absorb an immense of oil, releasing lubrication under pressure and reabsorbing it when at rest. The new Oilite springs eliminated leaf spring squeaks, starting in the 1932 Chrysler “Floating Power” CP and moving quickly throughout the company’s product line.
Amplex used the sintering process to save hundreds of thousands of hours of machinists’ time during the war, producing high-precision, quality products without waste or machining. The division made money during the Depression and would help Chrysler products’ durability, and Chrysler’s bottom line, for many years.
Carl Breer wrote that he suggested making a “porous powder strip metal in continuous form” to replace the expensive wire mesh then used as gasoline strainers in fuel tanks; gasoline was not as clean then as now. Breer suggested building a machine with two large, polished rollers, and pouring in mixed powdered metal which the powered rollers would push together into a thin sheet.
Their first attempt did not quite work, but they ended up being able to take the resulting sheet steel strips, heat treating them, and forming them into steel back type bearings.
Caulkins and the other engineers did eventually crack the puzzle, by making a globular powder of a uniform, small size, then sintering it into flat shapes; the strainer’s porosity was unifrm, and much more effective for straining gasoline than the expensive wire-woven filters. Breer wrote:
...one of our executives ran out of gasoline in the country one day. He stopped at a nearby farm house... and asked for a small pail of water. The farmer graciously complied... and saw the executive pour water into the gasoline tank. To the farmer’s astonishment, our executive stepped on the starter and away he went! What really happened was that our new strainer was so effective that it had let the gasoline through but not the water. When the water was added to the gasoline tank, it raised the little gasoline left in the tank to where the strainer would let it through, enough to let him make it to the nearest gas station.
Thus, Oilite started making fuel tank filters. An Oilite fuel filter in the gas tank was self-cleaned “by the sloshing action of gasoline in the tank.” A 1946 brochure noted, “Under the most rigid Army tests this was the only filter that met military requirements to prevent the passage of dirt and other impurities.” It removed the need for a glass sediment bowl at the fuel pump, and would remain standard through the 1950s.
By 1935, Amplex had a five-acre, nine-story plant in Detroit, with nearly 200,000 square feet of floor space, making air conditioning and heating equipment, marine and industrial engines, and other “high-grade specialties.”
In the 1950s, Amplex started making abrasives as well as lubricated parts and filters. Eventually, Amplex was moved to the Diversified Products Group, along with Airtemp, Cycleweld (which made adhesives, sealants, and petroleum products), and Marine and Industrial Engines. For 1959, Amplex launched “Iron Oilite grade A212” for bearings, along with other high density powdered iron parts; Amplex increased its production capacity accordingly.
In 1961, Amplex developed new metal-based friction materials for automotive use; at the time, it had plants in Trenton (MI) and Detroit, with an additional plant in Van Wert, Ohio, to be added before 1966. Amplex made its three billionth part in 1962, and in 1965, the Chrysler Amplex Division was the leading powdered metal parts maker, turning out over 6,000 different powdered metal products. By 1970, the division was also selling cold extrusion and ceramic magnet products.
In 1986, Norton Co. of Massachussetts bought confusingly-named Connecticut electroplator and abrasive maker Amplex; Norton kept the Amplex brand name and it is used to this day (2010) for abrasives.
On November 28, 1988, Amplex was sold in its entirety to ICM Industries, a privately held auto parts supplier founded by former International Harvester executives Rutherford and David Shelby. This move followed attempts in 1988 to sell the entire corporate parts division, then named Acustar, as GM would sell Delco and Ford would sell Visteon.
What happened to the former Amplex, a proud component of Chrysler Corporation for so many years? Just one year after buying Amplex, ICM Industries purchased Pullman Company’s Ferralloy metals division, with MAAG Gear-Wheel & Machine Co. of Zurich. They operated Ferralloy as a joint venture, and threw Amplex into the mix, renamed ICM/Krebsoge. The combined company had projected sales of $110 million per year, making principally powertrain components including timing gear sprockets and valve seat inserts and guides. The company remained in Detroit, and employed 1,150 people.
ICM/Krebsoge, which started out as the largest producer of powdered-metal parts in North America, was led in its early years by president and part-owner Kim E. Schatzel, a woman who started as a management trainee.
By 1993, ICM/Krebsoge was owned by holding company Powder Metal Holding. Cleveland-based Sinter Metals, Inc., which was on a buying binge, purchased 30% of PMH in 1993. Most of the former Amplex/Ferralloy’s sales went to the Big Three, but they also sold to Europeans including Daimler-Benz, Volkswagen, BMW, ZF, Bosch, and Opel.
In 1996, Sinter Metals, now the United States’ largest producer of powder metal components, purchased PMH (via ICM/Krebsoge), the second largest producer. The combined company was expected to have sales of $400 million per year; the purchase price was $215 million. In December 1997, Sinter Metals, Inc. was purchased by GKN plc, adding GKN Bound Brook and Asian joint ventures. Today, GKN Sinter Metals is the world’s largest producer of powdered metal components. (GKN was founded in 1902 as Guest, Keen & Nettlefolds Ltd in England, but traces its history to 1759’s creation of Dowlais Iron in Wales, 1854’s screw-making debut of John Sutton Nettlefold, and 1864’s IPO of Patent Nut & Bolt Co. by Arthur Keen.)