For use with drilling diameters over 3/4". These extensions feature hex shanks for maximum drill chuck grip, eliminating bit spin-out.

Fits both hex and round shank Forstner bits.

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Forstner Bit Speeds - Hard Woods

Bit Diameter	Top Speed (RPM)
1-1/2" to 3"+	450
1-1/16" to 1-7/16"	900
11/16" to 1"	1400
1/4" to 5/8"	1800

Forstner Bit Speeds - Soft Woods

Bit Diameter	Top Speed (RPM)
1-1/2" to 3"+	600
1-1/16" to 1-7/16"	1200
11/16" to 1"	1800
1/4" to 5/8"	2400

Forstner Bit Maintenance

Do not run your bits too fast, causing them to overheat. If your bit gets hot enough, the temper (hardness) can be removed from the bit. A blued bit is ruined.

Forstner Bits are made for nice, clean, precise holes and have limited uses in hand-drills. Ideally, these bits should be used in a drill press.

The best way to keep your Forstner Bits clean and in good operating order is accomplished by a good drilling technique. As you bore into a piece or material, pull the bit back up to the top rim of the hole to evacuate the chips. Forstner bits do not have flutes on them to remove the chips so it is necessary to do this approximately every 20 seconds of drill time.

Sharpening Suggestions

Most Forstner Bits come read to use but honing the chipper will improve their cutting action and longevity.

Hone only the flat portion of the chipper using a diamond hone or an Arkansas or Japanese stone. Start by using a 1000 Grit and working your way up to a 4000 Grit.

The rim of the bit can be sharpened using a round stone or diamond hone.

Remember not to change original cutting angle on your bit and keep the chippers slightly lower than the rim so that the rim cuts the edges of any fibers before the chippers remove any material.