Bits for Isoloc Joint Templates

Router Bits for Isoloc Joint Templates

High Quality Bits
Leigh Brand carbide-tipped router bits are among the best you can buy. They are made with high quality C2 and C3 micro grain carbide for long bit life. Each bit is honed to a fine edge with 600 grit diamond wheels for smooth, efficient routing. All shanks are 1-3/4" long to handle the thickness of the finger assembly or accessory template. Leigh router bits are manufactured to ISO 9002 standards.

For the best results, Isoloc joints should be routed with spiral upcut bits. Leigh offers two variants: high speed steel and solid carbide. The spiral upcut design routs cleaner, faster, leaves a smoother finish and dramatically reduces tear out. They are ideally suited for the smooth organic curves of Isoloc joints. Although both produce excellent results, the solid carbide versions are stiffer and hold a keen edge longer than the HSS. The performance of less expensive HSS bits is comparable to solid carbide but lose their edge more quickly. Choose the bit that best suits your needs and budget. Note: The Isoloc bit set 1617I is only available in solid carbide.


Shank Size
Bits with 5/16"(8mm) shanks require a 1/2" to 8mm collet reducer (Item 172-8) and bits with 3/8" shanks require a 1/2" to 3/8" collet reducer (Item 172-375).

Isoloc Joint Bit Selection

All standard Isoloc joints are routed with a 5/16" (8mm) diameter bit. Inlaid and shadow Isoloc joints require two additional router bits, specifically 1/4" and 3/8". Pin boards for regular Isoloc joints must be 3/4" thick or greater. Socket boards may be any thickness between 1/8" and 1 1/4". Leigh recommends the use of a plunge router for Isoloc joints. The cutting flute length of the bit (B) must be equal to or greater than the thickness of the tail board (B).

All Isoloc routing requires the use of the VGS Variable Guidebush System.


Isoloc Joint Bit Selection
Straight Bits
Rout the Pins
And Tails
Leigh Bits for
Isoloc Joints
Bit Diameter
Board Thickness
Overall Length
Joint Length

170 *
5/16" 1" 5/16" (8mm) 3" 5/8"



1/4" 1-1/8" 1/4" 3-1/2" 5/8"


170C *
5/16" 1-1/8" 5/16" (8mm) 3" 5/8"


173C **
3/8" 1-1/8" 3/8" 3" 5/8"


* Bits 170,170C require collet reducer 172-8
** Bit 173C requires collet reducer 172-375
* Solid Carbide bits are stiffer, rout cleaner and stay sharp longer


One 1/2" to 8mm collet reducer

One 1/2" to 8mm collet reducer 1 1/4" long. Required for all 8mm shank bits (70-8, 75-8, 80-8, 140-8, 170 and 170C).

Item no. 172-8


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One 1/2" to 3/8" collet reducer

One 1/2" to 3/8" collet reducer 1 1/4" long. Required for 3/8" shank bits (173C).

Item no. 172-375


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Bit Set for Isoloc Joint Templates


3-piece Solid Carbide Spiral Upcut Bit Set - Isoloc Joint Template

Includes 1/4" (168C), 5/16" (170C) and 3/8" (173C) bits.

For use with the Isoloc Joint Templates

Item no. 1617IC


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