Powermatic vs. Jet Bench Mortiser

There are several tools and methods to produce mortises, but they come with their own sets of advantages and disadvantages. Using a dedicated mortiser is the one true way to make high-quality, perfect-fitting mortises every time. One of the greatest benefits of using a mortiser is that it forces out wood debris while squaring the cut in one motion. This leaves a snug mortise that pairs flawlessly with tenons.

Powermatic Bench Mortiser

Powermatic 1791310 PM701

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Two well-known power tool manufacturers – Powermatic and Jet – make some of the industry’s most widely-used bench-top mortisers. The Powermatic PM701 and the Jet 708580 are popular for being moderately portable mortising machines to be used in practically any setting. They’re both great mortisers, but they come from two different worlds. The only question left is which of these two units performs better and provides greater value to the user. Keep on reading for an in-depth analysis of these two companies’ mortisers.

Jet Bench Mortiser

Jet 708580

Motor

Powermatic PM701
The PM701 features a ¾-horsepower motor running at 115 volts. This motor delivers up to 1,725 RPM. This is not the fastest motor out there, but at more than 1,500 RPM, it performs a lot quicker than other mortiser of the same weight and price range.

Jet 708580 JBM-5
The motor of the JBM-5 is slightly less powerful compared to the PM701. This mortiser features a ½-horsepower motor which also runs at 115 volts. Surprisingly, the machine can perform at up to 1,725 RPM as well, but working with thicker pieces of stock might cause a little too much strain on the underpowered motor.

Conclusion
The clear winner is the PM701 with its ¾-horsepower motor. Though underpowered when put up against industrial-grade mortising machines, it performs fairly well on thick stocks of wood.

Head-Stroke Capacity

Powermatic PM701
The spindle of the PM701 mortiser can travel up to 5-1/2 inches deep though DIY users most likely won’t need to make mortises that deep. It has a chisel-to-center distance of 4-3/8 inches and a maximum chisel capacity of ¾ inches. This mortiser truly is one of the most flexible ones available.

Jet 708580 JBM-5
The head-stroke capacity is pretty much what you’d expect on a smaller, lighter-weight mortising machine. The maximum depth the spindle can travel is limited to 4-3/4 inches, but the rack and pinion system allows for smooth operation. This machine has a maximum mortising capacity of ½ inches and a 3-1/2-inch chisel-to-center distance.

Conclusion
The PM701 is a little better in terms of chiseling depth. There’s nothing too great about the head-stroke capacities of these two machines, but they’ll work well for hobbyist furniture makers.

Powermatic Bench Mortiser2

Powermatic 1791310 PM701

Depth Adjustment

Powermatic PM701
The plunging motion is supported by a rack and pinion system which is mounted directly on the column. One great feature that Powermatic added to this PM701 is the placement of the depth stop directly onto the column to make contact with the head of the mortiser directly on the force line. This is a more accurate method of mortises of consistent depths.

Jet 708580 JBM-5
A hydraulic cylinder supports the plunging motion which is extremely helpful in retracting the chisel bits from stocks. This system helps raise and lower the weight of the motor located inside the head of the machine. The JBM-5 uses a stop rod to chisel mortises of consistent depths in multiple stocks.

Conclusion
Between the two machines, we like the depth-stop mechanism on the PM701 which is both easy and extremely accurate. The problem with stop rods is that they can rack the head, causing slight variations in chisel depth and angle. However, different users may feel more comfortable using the stop rod system of the JBM-5.

Jet Bench Mortiser

Jet 708580

Weight

Powermatic PM701
The overall weight of the PM701 is roughly 120 pounds. This is relatively lightweight compared to other bench-top mortising machines, but it is far from being considered “portable.” The weight helps in keeping the unit in place, but users will need to keep the mortiser in place using the corner mount holes.

Jet 708580 JBM-5
This device is far lighter than the PM701. It weighs in at only 44 pounds fully assembled, with the bulk of the weight coming from the head which encloses the motor. It’s a top-heavy unit so users need to keep the unit secured using the mount slots found on the corners of the base.

Conclusion
These bench-top mortising machines vary greatly in terms of weight. The PM701’s heavier weight class makes it perfect for use in a single workshop since it’s hard to transport from place to place. The JBM-5 is much lighter and thus more portable. However, the unit’s lightweight means you need to secure the base safely to whatever surface you place the unit on.

Powermatic Bench Mortiser

Powermatic 1791310 PM701

Lock and Fence

Powermatic PM701
This PM701 mortiser uses a dual-lock system to keep stocks in place with zero possibility for slippage. The first lock secures uses a finger knob to secure your stock from above. The second lock prevents wood pieces from shifting horizontally using the rack and pinion fence in combination with roller clamps. The clamps lock the wood safely against the fence while rollers let the board move left and right.

Jet 708580 JBM-5
Unlike the PM701, the mortiser uses a single-lock system with a vertical clamp which keeps the unit in place against the work table. To keep it moving horizontally, users are forced to use external clamps or hold it in place with their free hand. We would’ve liked to see this unit use a double system like the PM701 since even the tightest grip can be defeated by feeding the chisel and bit too quickly into stock.

Jet Bench Mortiser

Jet 708580

Powermatic PM701 vs Jet 708580: Conclusion
The double-lock system of the PM701 is superior to the single-lock and hand clamp combination in the JBM-5. The rollers are extremely smooth and let stock glide vertically on the work table.

Powermatic Bench Mortiser

Powermatic 1791310 PM701

Powermatic PM701 3/4-HP Bench Mortiser (1791310)
  • TWO INTEGRATED BIT AND CHISEL SPACERS: For quick set up.
  • IN-LINE DEPTH STOP: Allows stopping at pre-set depths without racking the bit to the base.
  • HEAVY-DUTY REVERSIBLE HANDLE: Can be installed (without tools) to either side of the head.

Last update on 2022-08-16 / Affiliate links / Images from Amazon Product Advertising API

Bottom Line

The clear winner is the Powermatic PM701 mortiser, though the Jet 708580 JBM-5 has its moments. Neither of these units is production machines, meaning that they work quickly but you can’t just plunge the bits into hardwood to make mortises.

The only aspect where the JBM-5 is superior to the PM701 is in terms of weight, if – and only if – you need a portable mortiser to take to various job sites. However, in terms of speed, performance, depth stops, and usage, the Powermatic mortising machine is the better choice.

Jet Bench Mortiser

Jet 708580

JET JBM-5 Benchtop Mortiser, 1/2HP, 115V 1PH, 1750...
  • Durability and Stability: Heavy-duty cast iron and steel construction.
  • Accurate Position Control: Dependable rack-and-pinion head adjustment.
  • Optimal Handle Position: Long, multi-position mortising handle lets you reposition the feed handle for easier...

Last update on 2022-08-16 / Affiliate links / Images from Amazon Product Advertising API


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