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Your cart is empty.Bosch self-feed drill bits are designed for the professional plumber and electrician who needs to make large, rough holes in wood. Bosch offers a complete line of wood boring bits for heavy-duty and fine woodworking applications.
Client d'
Reviewed in Canada on May 22, 2025
Parfait
Claude Manseau
Reviewed in Canada on March 22, 2025
J'ai du machiner la douille qui mesure 7/8" à l’extérieur et je devais percer 3/4". Autrement, c'est un bon produit
Ed
Reviewed in the United States on March 18, 2025
Great product & Great price!
Blue Hill
Reviewed in Canada on February 6, 2025
Just what I needed for my hole saw set. I need to make a hole in a deep recess. Bosch quality of course!
Michael P Nadeau
Reviewed in the United States on April 4, 2025
needed tool for any tool bag.
Kaleb Pruitt
Reviewed in the United States on September 11, 2024
Is decent heavy duty and make sure you lock everything in place and doesn't lock into place automatically
Sally Weise
Reviewed in the United States on August 24, 2024
Small hole saws have a 3/8" hex shaft, larger hole saws have a 7/16" hex shaft. This 12" extension fits the larger hole saws with a 7/16" shaft. It comes with the hex allen wrench to tighten the two screws that hold the hole saw in place. It works like expected and has the heft to last a lifetime. I went to a couple different farm supply stores and building supply places that did not stock this product and it came next day from Amazon. On-line sources had other brands at nearly twice the price.
Electronicbuff
Reviewed in the United States on July 20, 2024
This extension is heavy duty and works great. Contains 2 set screws to securely hold the cutter you are working with. We've enjoyed using this extension to get into hard-to-reach areas. The shaft is nice and thick so we don't need to worry it bending if the bit hits something solid.PROS:- Well made- Nice and thick for a solid connection- Has 2 set screws to securely hold your cutters- Fit in both our 1/2 and 3/8 (barely) chucksCONS:- None
Steven T.
Reviewed in the United States on February 24, 2024
If you have older auger bits (smooth shaft without a quick connect end) this extension, with hex screws that tighten down on the bit, is what you’ll need to effectively lengthen your bit. This extension worked flawlessly.
Vincent
Reviewed in Canada on November 5, 2024
Attached securely to forstener bit. No wobble when drilling.
Amazin Customer
Reviewed in Canada on September 15, 2023
This is legit, holds 11mm or 7/16" as advertised. Works great.
Greg Leatherwood
Reviewed in the United States on May 1, 2023
This Bosch bit extension is a beautifully made, precision tool accessory. It is accurately machined to accept 7/16" bits. Don't be misled by its low price, this is a high-quality product. Highly recommended.(I previously ordered a no name 7/16" drill bit extension on Amazon. The no-name extension was poorly machined despite costing over twice as much — the female end would not accept my DeWalt 7/16" bit. I ordered this Bosch extension to replace it. The Bosch extension is accurately machined and works perfectly! Don't repeat my mistake — order the Bosch extension the first time).
Jason
Reviewed in the United States on November 24, 2023
I purchased this extension to cut holes through my brick walls for mini split installation. Well made heavy duty extension. I almost didn’t buy this one because it doesn’t show the set screws in pictures. It does have set screws and also comes with Allen wrench to tighten them.
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