About the Allis-Chalmers IB
The IB was Allis-Chalmers' industrial version of the Model B. It kept the compact four-cylinder layout but added a heavier frame and front axle, along with a foot throttle for industrial work.
IB tractors built before 1946 shared the serial-number sequence used by the farm Model B. From 1946 onward, the IB used its own IB-prefixed serial numbers, and the model continued into the 1950s.
Serial Number Reference
Serial number locations: The tractor serial number is stamped behind the gear shift lever on top of the transmission case. The engine serial number is on the rear left-hand side of the engine between the carburetor and fuel filter.
The table below shows the beginning tractor serial number for each Model IB year:
1938-1943
| Model IB year |
Beginning serial number |
| 1938 - Shared with Model B |
97 |
| 1939 - Shared with Model B |
11,800 |
| 1940 - Shared with Model B |
33,502 |
| 1941 - Shared with Model B |
49,721 |
| 1942 - Shared with Model B |
56,782 |
| 1943 - Shared with Model B |
64,501 |
1944-1948
| Model IB year |
Beginning serial number |
| 1944 - Shared with Model B |
65,502 |
| 1945 - Shared with Model B |
70,210 |
| 1946 - IB serial prefix |
IB1001 |
| 1947 - IB serial prefix |
IB1003 |
| 1948 - IB serial prefix |
IB1010 |
1949-1953
| Model IB year |
Beginning serial number |
| 1949 - IB serial prefix |
IB1282 |
| 1950 - IB serial prefix |
IB1556 |
| 1951 - IB serial prefix |
IB1879 |
| 1952 - IB serial prefix |
IB2219 |
| 1953 - IB serial prefix |
IB2570 |
1938-1945
| Model IB year |
Beginning serial number |
| 1938 - Shared with Model B |
97 |
| 1939 - Shared with Model B |
11,800 |
| 1940 - Shared with Model B |
33,502 |
| 1941 - Shared with Model B |
49,721 |
| 1942 - Shared with Model B |
56,782 |
| 1943 - Shared with Model B |
64,501 |
| 1944 - Shared with Model B |
65,502 |
| 1945 - Shared with Model B |
70,210 |
1946-1953
| Model IB year |
Beginning serial number |
| 1946 - IB serial prefix |
IB1001 |
| 1947 - IB serial prefix |
IB1003 |
| 1948 - IB serial prefix |
IB1010 |
| 1949 - IB serial prefix |
IB1282 |
| 1950 - IB serial prefix |
IB1556 |
| 1951 - IB serial prefix |
IB1879 |
| 1952 - IB serial prefix |
IB2219 |
| 1953 - IB serial prefix |
IB2570 |
1938-1953
| Model IB year |
Beginning serial number |
| 1938 - Shared with Model B |
97 |
| 1939 - Shared with Model B |
11,800 |
| 1940 - Shared with Model B |
33,502 |
| 1941 - Shared with Model B |
49,721 |
| 1942 - Shared with Model B |
56,782 |
| 1943 - Shared with Model B |
64,501 |
| 1944 - Shared with Model B |
65,502 |
| 1945 - Shared with Model B |
70,210 |
| 1946 - IB serial prefix |
IB1001 |
| 1947 - IB serial prefix |
IB1003 |
| 1948 - IB serial prefix |
IB1010 |
| 1949 - IB serial prefix |
IB1282 |
| 1950 - IB serial prefix |
IB1556 |
| 1951 - IB serial prefix |
IB1879 |
| 1952 - IB serial prefix |
IB2219 |
| 1953 - IB serial prefix |
IB2570 |
Total production: 2,850 Model IB tractors.
