Ask anyone who restores old saws which cabinet saw to buy, and the answer is nearly always one of two: a Delta Unisaw or a Powermatic 66. They were rivals for decades, both are 10 in tilting-arbor saws with the motor inside a closed cabinet, and both turn up used, often out of school shops. They're more alike than the arguments suggest, and the right one is usually whichever complete saw with the right motor is nearest to you. The differences are real, though, mostly in the motors, the fences and how easy parts are to find.
Where they came from
The Unisaw is the older design. Delta brought it out in late 1938 as the No. 1450, and from the 1950s into the 1980s it sold under Rockwell as the 34-450 bare saw, the 34-451 with wings and guard, and a long run of package numbers. After Milwaukee closed in 1952, Unisaws were built in Tupelo, Mississippi. The 1980s 34-80x saws came after Pentair bought Delta's machinery business in 1984.
The Powermatic 66 first appears in Powermatic's 1965 catalog, built in McMinnville, Tennessee. The 1963 and 1964 catalogs list only the earlier Model 65. Powermatic kept building the 66 through ownership by Houdaille, Stanwich and then Jet's owner WMH, and its 1998 catalog still called it made in the USA.
Motors and drive
Both hide a belt-driven motor in the cabinet, and both were sold with single-phase and three-phase motors. Delta's 1961 catalog offered Unisaw packages with a 1-1/2 HP single-phase motor at 115/230 V or a 2 HP three-phase motor, and its mid-1980s manuals list 1-1/2 HP single-phase with a push-button switch and 1-1/2 or 3 HP single-phase or 3 HP three-phase with a magnetic starter. Every Unisaw drives the arbor with three belts.
Powermatic's 1965 catalog gave the 66 motors from 1-1/2 to 3 HP in single or three-phase, and by 1989 the list ran from a 2 HP manual-switch saw to 5 HP in single or three-phase. The 66 hangs its motor on a C-flange mount at the saw-arm pivot, which Powermatic said keeps the motor's weight off the arbor. Early saws used three V-belts and later ones two 3VX belts.
So a late Powermatic offers more power at the top end, and both saws are easy to find with a single-phase motor. Whichever you look at, read the motor plate first, and see our guide to three-phase power at home if it's three-phase.
Arbor, trunnions and tilt
Both take ordinary 10 in blades on a 5/8 in arbor, and Powermatic offered a 3/4 in arbor as an option in 1965. Delta's Unisaw parts list calls for 17 x 40 mm ball bearings, and the 66 uses sealed ball bearings from NSK, so either is a standard bearing job.
Powermatic made a point of its one-piece, wide-stance cast-iron trunnion, and the 66's blade tilts left, away from the fence. The Unisaw changed in small ways over the decades, and Delta's parts list marks some changes at serial DC-8366, around 1964. On either saw, the test is the same. Crank the blade from full height to the bottom and tilt it to 45 degrees. Both wheels should turn smoothly, and packed sawdust is the usual reason they don't.
Fences
The fence is where the two saws differ most from year to year, and it changes a used saw's value more than anything except the motor.
- Unisaw: the Jet-Lock fence from 1960, then in the 1980s the aluminum-body Jet-Lock, the Unifence or a Biesemeyer, depending on the package. Delta bought Biesemeyer in 1995.
- Powermatic 66: Powermatic's own Positrack round-rail fence on early saws, a Biesemeyer T-square as standard by 1989 (with a Vega fence on one 2 HP version), and Powermatic's Accu-Fence as standard by January 1997.
A T-square fence like the Biesemeyer, Unifence or Accu-Fence is what most woodworkers want. Check that the rails are there and the fence locks square, because rails in the right length are the hard part to replace.
Weight
Powermatic's brochure boasted that the 66 weighed far more than its leading competitor. On paper, Delta's 1961 catalog lists the bare Unisaw at 279 lb and a complete single-phase package at 422 lb, both shipping weights. Powermatic's 1979 manual gives 450 lb net with motor, and the 2005 manual lists 614 lb shipping with motor, fence and rails. Either way you're moving well over 400 lb, which means freight or a trailer and helpers. Our guide to shipping a heavy machine covers how.
Parts
This is where the Unisaw has an edge. Powermatic says parts for its made-in-USA machines are no longer being made, and its old parts stock went to a dealer that has since closed. Delta's Unisaw parts lists and manuals are on VintageMachinery.org, and Delta itself sold Unisaws with Biesemeyer fences in the 1980s. Standard bearings and belts are easy for both, but a missing Powermatic guard, insert or fence part takes more hunting.
Dating each one
Unisaws date by the plate address (Milwaukee through 1952, Pittsburgh after), Delta's serial tables and the running changes: the Jet-Lock in 1960, T-slots in 1961, a sheet-metal motor cover from 1967 and a sheet-metal base from 1977. From 1982 the serial is a date code that starts with the year.
Powermatic 66 serials go 66-nnn from 1965 to 1968, then one year digit and 66 (like 866) to 1977, then two year digits and 66 from 1978. The paint confirms it, green through 1981, gold from 1982 to 1995 and mustard yellow after. A mid-1997 change also painted the inside of the saw, including the trunnion, and gave the stand an enclosed, angled bottom. Our guide to dating old iron by serial number has the full tables.
Which to buy
Buy the one that's complete. A Unisaw or a 66 with its fence and rails, its guard and splitter, the wings and a motor your shop can run is a saw you won't need to replace. If you're choosing between two complete saws:
- Pick the Unisaw if parts matter most, or you want a 1950s or 60s saw with cast-iron details.
- Pick the Powermatic 66 if you want the extra weight, a one-piece trunnion or a 5 HP motor on a later saw.
- Pick either over a cheaper one with a missing fence or a three-phase motor you haven't budgeted for.
Then run the listing through the model page's checklist and our guide to checking a used machine before you agree a price.
