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To remedy this issue we have developed a heavy duty steel extension that allows you to secure a 3/8 inch shank forstner bit into the end collet. Drilling with forstner bits to achieve a flat bottom hole or to start a deep hole turning project like on a larger vase or vessel is essentially impossible with a standard length forstner bit.
It is designed to be used with forstner bits only. The collet inside diameter is 3/8 inch. This tolerance is very tight and designed to accept forstner bits with shank sizes of 3/8 inch or slightly smaller. The forstner bit extender is made from solid, heavy duty machined steel. This means the set screws may protrude outwardly from the collet. Please note that some forstner bit manufacturers produce bits that say 3/8 inch shank size when in fact they are not.


The collet outside diameter is 25/32 inch without the set screws protruding outward. The forstner bit extension gives you additional 8-1/2 inches of reach to bore deeper into your projects.
The collet inside diameter is 3/8 inch. This means the set screws may protrude outwardly from the collet. This will help you create larger diameter starter holes or help when you need to drill in just a little further than the standard bit length will allow. The minimum size hole this extension will allow you to drill is 13/16 inch. If you measure your bit shank and it is 3/8 inch, your bit should fit once the set screws are loosened.




Perfect for the toughest jobs – the black phosphate coating Treatment will make sure that your rust-proof and corrosion-resistant drill to socket adapter will endure any abuse.
For a lifetime of successful projects – meet & exceeds ansi the american national Standard Institute and backed by our Lifetime Limited Warranty for your complete peace of mind.
1. Lenox Tools
#ad
LENOX Tools Hole Saw Extension Chuck, 10-Inch x 3/8-Inch 3084310X
#adLenox Tools #ad - Extension is compatible with 5L and 6L SNAP-BACK arbors. Hardened carbon steel for strength. 3/8" or larger chuck size. Fits 5l, 6l and 7l solid-hex arbored hole saws.More information #ad
Brand | Lenox Tools #ad |
Manufacturer | Lenox Tools #ad |
Height | 0.75 Inches |
Length | 12.5 Inches |
Weight | 0.62 Pounds |
Width | 2.88 Inches |
Part Number | 3084310X |
Model | 3084310X |
More information #ad
2. Century Drill & Tool
#ad
12In. 38112, Century Drill & Tool Ship Auger Extention, 3/8 In. Shank
#adCentury Drill & Tool #ad - Securely grips ship auger drill bits for extended length. Extension’s shank fits ½" drill chucks. 12" length. For use with ship auger bits with 3/8” hex shanks.More information #ad
Brand | Century Drill & Tool #ad |
Manufacturer | Century Drill & Tool Corp #ad |
Height | 0.75 Inches |
Length | 12 Inches |
Weight | 0.84 Pounds |
Width | 0.75 Inches |
Part Number | 38112 |
Model | 38112 |
More information #ad
3. Fulton
#ad
Carpentry and Construction, Furniture, Fulton 6 inch Long Forstner Bit Extension for Adding Over 5-5/8 inches of Drilling Depth to Your Forstner Bit. for Wood Turners
#adFulton #ad - The extension can be used with forstner bits on drill presses, lathes with a drill chuck installed drill chuck not included or with a power drill. This will help you create larger diameter starter holes or help when you need to drill in just a little further than the standard bit length will allow.To remedy this issue we have developed a heavy duty steel extension that allows you to secure a 3/8 inch shank forstner bit into the end collet. Drilling with forstner bits to achieve a flat bottom hole or to start a deep hole turning project like on a larger vase or vessel is essentially impossible with a standard length forstner bit.
More information #ad
The forstner bit extension gives you additional 5-5/8 inches of reach to bore deeper into your projects. If you measure your bit shank and it is 3/8 inch, your bit should fit once the set screws are loosened. It is designed to be used with forstner bits only. The collet inside diameter is 3/8 inch. This tolerance is very tight and designed to accept forstner bits with shank sizes of 3/8 inch or slightly smaller. The forstner bit extender is made from solid, heavy duty machined steel. This means the set screws may protrude outwardly from the collet. Please note that some forstner bit manufacturers produce bits that say 3/8 inch shank size when in fact they are not.
Brand | Fulton #ad |
Manufacturer | Fulton Woodworking Tools and Accessories #ad |
Part Number | 927 |
More information #ad
4. IVY Classic
#ad
High Carbon Steel, IVY Classic 46152 4-Inch Forstner Bit Extension, 1/Tube
#adIVY Classic #ad - Ideal for use with any 3/8" shank bit. Extends any forstner shank bit an additional 4 inches, Swift Bore Registered Trademark. High-carbon steel construction, precision ground and polished.More information #ad
To fasten the shank in place, use the hex key to tighten these screws. Shank: 3/8-inch, length: 4-inch. Two set screws and hex key included.Brand | IVY Classic #ad |
Manufacturer | IVY Classic Industries #ad |
Height | 0.63 Inches |
Length | 4 Inches |
Weight | 0.03 Pounds |
Width | 0.63 Inches |
Part Number | 46152 |
Model | 46152 |
More information #ad
5. Fulton
#ad
Fulton 10 inch Long Forstner Bit Extension for Adding Over 8" of Drilling Depth to Your Forstner Bit Ideal for Wood Turners Furniture Carpentry and Construction 3/8 inch Collet
#adFulton #ad - The reason this is important is that as we mentioned earlier, some bits may have slightly different shank sizes. This tolerance is very tight and designed to accept forstner bits with shank sizes of 3/8 inch or slightly smaller. One of the most common uses for the forstner bit extension is for woodturners who need to bore out starter holes on larger vessels.The collet outside diameter is 25/32 inch without the set screws protruding outward. The forstner bit extension gives you additional 8-1/2 inches of reach to bore deeper into your projects.
More information #ad
The forstner bit extender is made from solid, heavy duty machined steel. The extension can be used with forstner bits on drill presses, lathes with a drill chuck installed drill chuck not included or with a power drill. To remedy this issue we have developed an extra long, heavy duty steel extension that allows you to secure a 3/8 inch shank forstner bit into the end collet. The collet inside diameter is 3/8 inch. This means the set screws may protrude outwardly from the collet. This will help you create larger diameter starter holes or help when you need to drill in just a little further than the standard bit length will allow. The minimum size hole this extension will allow you to drill is 13/16 inch. If you measure your bit shank and it is 3/8 inch, your bit should fit once the set screws are loosened.
Brand | Fulton #ad |
Manufacturer | Peachtree Woodworking Supply Inc. #ad |
Part Number | 200-2206 |
Model | 2206 |
More information #ad
6. Irwin Tools
#ad
5-1/2",Silver, IRWIN 4935652 Lock-n-Load Quick Change Extension
#adIrwin Tools #ad - 5-1/2" overall length. The bit extension has a patented jaw design with 6-flatted shanks to hold bits securely. Each irwin quick-change bit holder features a carbon-steel sleeve and body for durability. These bit holders use the Lock-n-Load system for 1-handed quick release.More information #ad
The bit extension has a patented jaw design with 6-flatted shanks to hold bits securely. Each irwin quick-change bit holder features a carbon-steel sleeve and body for durability. 5-1/2" overall length. These bit holders use the Lock-n-Load system for 1-handed quick release.Brand | Irwin Tools #ad |
Manufacturer | IRWIN #ad |
Height | 7.75 Inches |
Length | 0.88 Inches |
Weight | 0.2 Pounds |
Width | 1.75 Inches |
Part Number | 4935652 |
Model | 4935652 |
More information #ad
7. Freud
#ad
DHS375XT12, Freud-Diablo 3/8 X 12 SNAP Lock, Multicolor
#adFreud #ad - Diablo 3/8 x 12 snap lock. Diablo 3/8 x 12 snap lock. Diablo 3/8 x 12 snap lock. Diablo 3/8 x 12 snap lock. Diablo 3/8 x 12 snap lock.More information #ad
Brand | Freud #ad |
Manufacturer | Freud #ad |
Height | 1 Inches |
Length | 1 Inches |
Width | 1 Inches |
Part Number | DHS375XT12 |
Model | DHS375XT12 |
More information #ad
8. Taytools
#ad
Taytools 774403 6-3/4 inch Round Shank Forstner Drill Bit Extension for 3/8 Inch Round or Hex Shafts
#adTaytools #ad - Can be used in a hand drill, drill press or lathe. Hole opening is. 375 inches and hole depth 1-3/8 inches. Made from precision machined steel. Note: will fit auger bits. This round shank forstner bit extension will extend the reach of any Forstner bit 3/4 inch and larger with a 3/8” hex or round shank.More information #ad
Overall length 6-3/4 inches and adds up to 5-5/8 inches of drilling depth. Hex wrench included. Contains two set screws for a secure grip on bits.Brand | Taytools #ad |
Manufacturer | Taylor Toolworks #ad |
Part Number | 774403 |
More information #ad
9. LEXIVON
#ad
Adapt Your Power Drill To High Torque Impact Wrench LX-101, LEXIVON Impact Grade Socket Adapter Set, 3/8", 3" Extension Bit With Holder | 3-Piece 1/4", and 1/2" Drive
#adLEXIVON #ad - One set of impact socket adapters, unlimited uses – the ¼” hex shank will fit all quick Change systems and standard drill chucks, which is ideal for both professionals and DIYers. Must-have heavy duty tools for your toolbox – our 3 x impact grade adapters are made from heat treated Chrome Vanadium steel and come in a convenient organizer/holder.Perfect for the toughest jobs – the black phosphate coating Treatment will make sure that your rust-proof and corrosion-resistant drill to socket adapter will endure any abuse.
More information #ad
Save your time & effort – the chamfered edges and spring-loaded detent ball will ensure a tight and secure fit, thus allowing you to save your precious time and perform auto repair tasks easily. For a lifetime of successful projects – meet & exceeds ansi the american national Standard Institute and backed by our Lifetime Limited Warranty for your complete peace of mind.
Brand | LEXIVON #ad |
Manufacturer | LEXIVON #ad |
Height | 0.5 Inches |
Length | 3 Inches |
Width | 0.5 Inches |
Part Number | LX-101 |
Model | LX-101 |
More information #ad