M2 / M2M
M2/M2M Multiple Mortise & Tenon Attachment
Mount this Attachment on your D4R Pro or D-Series Jig
Fits all 24" [610mm] D4R Pro, D4R, D4, D3, D1258 and D1258R Jigs

The M2/M2M is no longer in production or available directly from Leigh.
Select authorized dealers may have stock.  Please contact Customer Service at 1800-663-8932

Leigh’s Multiple Mortise & Tenon Attachment (M2 or M2M) brings this challenging joint within easy reach of any woodworker who owns a D4R Pro or D-series dovetail jig and a plunge router with 1/2" collet. The M2/M2M’s adjustable guide fingers let you rout multiple mortise & tenon joints in virtually any layout you like, in stock up to 24" (610mm) wide. Mortises & tenons can be routed in sizes from a delicate 5/16" x 5/8" (7.93 x 15.9mm) to a muscular 1-1/2" x 2-1/2" (38.1 x 63.5mm). Choose from two corner radii: 5/32" and 1/4", plus square with chiseling. Rout mortise & tenon joints in virtually any layout, in stock up to 24" wide.

Play Video

M2 Multiple Mortise & Tenon Attachment Overview video

Create all this with the M2 / M2M

The M2/M2M attachment helps you rout the perfect joint to suit any woodworking project.

Through Multiple Mortise & Tenon Joints
  • Benches, bookcases, coffee tables
Through Multiple Mortise & Tenon Joints
  • Endless variations
Through Multiple Mortise & Tenon Joints with Pegs
  • Knock down furniture
Wedged Through Multiple Mortise & Tenon Joints
  • Sophisticated looking joinery
Jumbo Box Joints, Variably Spaced, Raised
  • Strong joints for shelving, boxes, benches
  • Box lids and cabinet hinges
Simple Setup and Operation

Remove the guide finger assembly and slide the M2 attachment onto your jig in seconds.

Guide Bushings

All routing on the M2 requires the use of a guidebush (guide bushing). Choose either a 7/16" OD guidebush when using a 5/16" bit, or a 5/8" OD guidebush when using a 1/2" bit. The guidebush attaches to the base of the router and is fixed (doesn’t rotate). The bit goes through the guidebush and fits in the router collet. Note: You may also need an adaptor for your router. Learn more in Router Requirements section below. Click here for the Guide Bushing Adaptor Selector

Jumbo Finger (Box) Joints

The M2/M2M can also rout extraordinary jumbo variably spaced finger (box) joints. Finger Joints are almost always made with identical finger and socket sizes, but since fingers are basically multiple tenons, and sockets are simply a series of mortises, Leigh’s M2 is a finger Joint jig right out of the box. The M2/M2M makes fingers 5/8" or wider, symmetrically or variably spaced, just like Leigh dovetails. The M2 handles stock as thick as 1-1/2".

Router Requirements

What Router Should I Use?

Leigh recommends a midsize router, from 1-1/2 to 2-1/4 HP (9-13 amps) with a 1/2” collet. This size provides great power to weight ratio. Fixed base routers are ideal because they have a lower center of gravity with handles mounted to the router base rather than the motor, as with plunge routers. However, if you are proficient with the use of a plunge router, it works just as well. A plunge router is recommended for Isoloc Templates and is required for the M2 Attachment. When buying a router, also consider ergonomics, switch location, a good plunge mechanism and easy, accurate adjustment of bit height.
Guide Bushing Adaptors for your Router

All Leigh Dovetail & Box Joint Jigs need a router fitted with a Leigh guide bushing. Because the router industry isn’t standardized, you may need an adaptor to fit the guide bushing to your router. Click here for the Guide Bushing Adaptor Selector

Router Collets

The M2/M2M requires a router with a 1/2" collet, and smaller bits require the use of collet reducer. Learn more >

Leigh Brand Router Bits

One or two bits are all you need for the M2/M2M. A 1/2" bit (Leigh No.180) is included with the M2 attachment. It’s suited to heavier joinery in boards 3/4" to 1-1/2" thick. It cuts quickly and smoothly with a larger corner radius. A 5/16" bit (Leigh No.170) is available as an optional bit and is used for relatively small mortise & tenon joints in boards 3/4" or thinner. It leaves a nice, tight radius in the corners.
Note: Leigh does not sell metric bits.

How to Rout Multiple Mortise & Tenon Joints with the M2/M2M
1 Mount the M2 /M2M template on your D4R Pro jig in mortise mode. Color-coded scales for 1/2" (12.7mm) or 5/16" (7.9 mm) bits gives you precise control of mortise width.
2 Upcut spiral bits are your best choice for routing mortises and tenons cleanly. Use a 5/16" bit with a 7/16" o.d. guidebush, or a 1/2" bit (included) with an optional 5/8" o.d. guidebush.
3 Adjust the fingers to the multiple mortise and tenon layout you’ve designed. The template guidebush steers your router against the fingers through three sides of the mortise. An adjustable fence, the mortise beam, guides your router base as you cut the fourth side. Set your depth of cut for either blind or through mortising.
4 Remove the mortise beam and flip the finger assembly over into tenon mode.
5 While the finger layout establishes the width of your tenons, the scales determine their thickness.
6 Routing square-cornered tenons is very quick and straightforward. Rounding their corners is a simple twostep process, aided here by using shop-made wooden bridges between guide finger ends.
Technical Specifications
Multiple Mortise & Tenon Joints
1 Tenon Width 5/8" [15.9mm] 2-1/2" [63.5mm]
2 Tenon Length (Blind or Through as required) 1-1/2" [38.1mm]
3 Tenon Thickness Square Tenon 5/16" [7.93mm] 1-3/8" [35mm]
4 Finger (Box) Joints 5/8" [15.9mm] and up, variable
Each M2 Attachment includes:
24" M2 Attachment
Two side stop extensions
1/2” HSS spiral upcut bit (Leigh no.180)
Hex key
Support Brackets for models D3 and earlier
Fully illustrated user guide
1/2" to 8mm collet reducer
1-1/4" long.

The M2/M2M requires a router with a 1/2" collet and a 1/2" to 8mm collet reducer.

Item no. 172-8


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711C – 7/16" OD Elliptical Guide Bushing
For joints routed on the M2/M2M. Use with 5/16" (7.9mm) HSS spiral upcut bit, no.170.
Item no. 711C


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716C – 5/8" OD Elliptical Guide Bushing
For jumbo joints routed on the M2/M2M. Use with 1/2" (12.7mm) HSS spiral upcut bit, no.180.
Item no. 716C


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