Aluminum Block Planes from the Stanley Model Shop
In the first couple of decades of the 20th century, aluminum became available to manufacturers at a reasonable cost. Although aluminum comprises 8.2% of the earth’s crust, making it the most abundant metal in nature, it never occurs in its free form. In 1825, Hans Christian Oersted, a Danish chemist, was the first to produce small amounts of free aluminum. It remained extremely expensive to produce aluminum until Charles M. Hall, a young American chemist, and Paul Héroult, a French chemist, almost simultaneously invented a process in 1886 for obtaining aluminum oxide at a reasonable cost. German scientist Karl Joseph Bayer developed a process to obtain aluminum from bauxite a few years later, and the Hall and Bayer processes are used to this day to produce aluminum. Hall founded the Pittsburgh Reduction Company in 1888 which eventually became Alcoa (The Aluminum Company of America). Hall’s first products were tea kettles and pots and pans, but it didn’t take long for other manufacturers to appreciate the advantages of aluminum. Count Ferdinand Zeppelin used aluminum to make the frames for his Zeppelin airships. In 1903, the Wright brothers used a cast aluminum crankcase in their first airplane to save weight. This was the first time aluminum was used in the construction of an aircraft engine. By the First World War the Germans produced the first full metal aircraft, the Junkers J1 monoplane that was built primarily from aluminum.
Aluminum continued to gain popularity and found increasing uses after the First World War. Stanley paid attention to these developments as well. On April 28, 1915 the Stanley Rule and Level Operating Committee voted that “…the Manufacturing Department be authorized to make 11 #45 planes the same as the regular #45 made to Spec. #1111, with the following exceptions – the main stock, Fence, Fence Plate, and Sliding Section to be made of Aluminum, the finish on these parts to be brushed and lacquered, and that the Inspection and Packing Departments be authorized to accept these goods.”
Despite these instruction from the Operating Committee, Stanley did not offer any aluminum planes for sale in their catalogs until 1925, when an expanded line of Stanley aluminum planes were offered for sale in the Stanley No.34 catalog. They included the A4, A5, and A6, bench planes, and the A18 block plane (See Fig. 1). The A78 duplex rabbet and filletster plane and the A45 combination plane were added to this line in the 1926 Stanley No. 34 catalog(See Fig. 2). These planes were identical to the same Stanley planes offered in cast iron but the bodies, frogs, and fences were made of aluminum and no japanning was done on these planes. They were significantly lighter than their cast iron counterparts and were about 30 percent more expensive .
Stanley didn’t aggressively market or advertise their line of aluminum planes. They were lighter weight, didn’t rust, and were not likely to crack or break like cast iron when dropped, all of which were good selling points. However, the aluminum planes when used, tended to discolor the wood, leaving black marks that were hard to remove. They also wore unevenly and the aluminum bodies were subject to scratches and dings if not handled carefully. Stanley also had the misfortune of introducing these planes just prior to the onset of the Great Depression and their extra cost didn’t help sales, so these aluminum bodied planes were removed from production in 1935.
You’d think that Stanley had learned their lesson the first time, but here are two aluminum block planes from the Stanley Model Shop that prove they at least thought about trying it again (See Fig. 3). The first plane is identical to a Stanley #110 block plane, but instead of cast iron, the body of this plane is cast aluminum with prominent milling marks on the sidewalls. It is 7 and 1/8th inches long, 2 inches wide and has a 1 and 5/8ths inch cutter. A 1/32nd of an inch-thick piece of polished rolled steel has been glued to the bottom of the plane, most likely to overcome the problem of black marks being left on the planed surface by the aluminum and to minimize the scratching and gouging of the plane sole that was so common on Stanley’s earlier aluminum planes (see Fig. 4).
There are no casting marks or numbers on the body of the plane. The front knob is stained hardwood screwed onto a coarsely threaded post on the toe of the plane. The lever cap is nickel plated cast iron with the number “12” and the letter “B” stamped on its inner surface. The lever cap adjusting screw is made from stamped steel. These stamped steel lever cap adjusting screws appeared in the Stanley Full Line catalogs in the mid 1980’s placing this plane squarely in that time period (See Fig 5).
About 1979 Stanley changed the cutter adjusting mechanism and the method of attaching the lever cap on their #220 block plane that they had produced continuously since 1898. (See Fig 6). The cutter adjusting mechanism on the earlier versions of the #220 block plane was based on patent #645,220 awarded to Justus Traut on March 13, 1900.
While the adjustment mechanism on the post 1979, #220 block planes looks different, it operates using the same principle as seen on the earlier versions of the plane. A bent strap with a small nib on the forward end is attached to the shaft of the adjustment knob. Corresponding slits in the cutter fit over the small nib. Turning the knob moves the cutter to increase or decrease the depth of cut. It is a surprisingly sensitive adjustment mechanism and works very well. The front knob is stained hardwood . The lever cap on these planes was also different from the lever caps seen on the earlier version of the #220 block plane. Made of aluminum that was painted black, the lever cap has a hole that fits over a threaded rod screwed into the bed of the plane. Pressure is applied to the cutter by tightening a knurled thumb nut onto the threaded rod.
The second aluminum block plane from the Model Shop shown in Figure 7 is identical to the cast iron version of the #220 but is made of aluminum. Like the cast iron version, it is 7 inches long, 2 and 1/16th inches wide and has a 1 and 5/8ths inch wide cutter. The lever cap is identical to that of the #220 cast iron block plane but it is polished instead of painted and the front knob is stained hardwood that is pressure fitted onto a short post on the toe of the plane (the cast iron version has a threaded post on the toe to accept the front knob, See Fig. 8).
The cast iron version has U.S.A. cast in raised letters on the heel of the plane body while the aluminum version has “MADE IN USA” cast in raised letters on the heel of the plane body. Both lever caps have “1” and “AA” cast into the back of the lever cap but have different casting numbers on the bed of the plane just behind the mouth (see Fig. 9). This plane also dates to the late 1970’s or early 1980’s.
Neither one of these planes made it out of the Model Shop and into production. Stanley was actively shifting it’s production of woodworking planes from the United States to England during the decades of the 1970’s thru the 1980’s and didn’t seem to be very interested in producing high quality woodworking planes. These two block planes are in pristine condition and don’t look like they were ever used on a piece of wood. Despite the ongoing shift of plane production to England, the guys in the Model Shop were still active and produced these planes in the U.S. But it appears that the decision makers at Stanley decided that the idea of an aluminum plane was no better in the 1980’s than it was in the 1920’s. And yet, the existence of these two Stanley Model Shop aluminum block planes proves that, “what goes around comes around”. Stanley is still producing both the #110 block plane (first introduced in 1874) and the #220 block plane (first introduced in 1898) and these two block planes have been in continuous production in one form or another since their introduction all those years ago.
Paul Van Pernis
 Heckel, David E., The Stanley “Forty-Five” Combination Plane, Forty-Five Publishing, Charleston, Illinois, 2002, p.77. Original source for this information was microfilmed minutes of the Stanley Rule & Level Company Operating Committee Minutes, April 28, 1915, courtesy of Clarence Blanchard. Heckel’s book is an excellent resource for anyone interested in learning more about Stanley’s combination planes.
 Dave Heckel has discovered that the earliest listing in a Stanley No. 34 catalog of their aluminum planes was a September 1924 insert that was placed in a 1922 British Edition Catalog No. 34. It shows the A4, A5, A6, and the A 18. The earliest American catalog listings for their aluminum planes were the 1926 Stanley pocket catalog and the No. 34 catalog.
 Cast Iron Plane Cost -1926 Aluminum Plane Cost – 1926
No. 4 $ 4.40 No. A4 $ 5.80
No. 5 $ 5.00 No. A5 $ 6.60
No. 6 $ 6.50 No. A6 $ 8.80
No. 18 $ 3.00 No. A18 $ 3.50
No. 78 $ 3.30 No. A78 $ 4.20
No. 45 $15.00 No. A45 $20.00
 This version of the #220 block plane was made for a very short time. It first appears in the 1979/1980 Stanley Tools Full Line Catalog and by 1993 it was replaced by an alternate version of the #220 with a new locking lever cap, slightly different depth of cut adjuster, an added lateral cutter adjuster and a “moulded textured plastic finger grip.” Stanley started shifting the manufacture of woodworking planes from the U.S. to their plant in Sheffield, England starting in 1971. This shift continued and by 1989 all woodworking plane production was done in Stanley’s plant in Sheffield, England. (Many thanks to EAIA member Walter Jacob for providing the information on the shift of manufacturing from the U.S. to England!)T By 2008, Stanley woodworking plane manufacturing once again moved, this time to Mexico. Most Stanley plane users prefer planes made by Stanley prior to World War II.