The Festool 494446 Replacement Drill Bit is a 4.5 mm replacement bit set made for the Festool countersink system. This is a replacement drill bit designed for restoring the pilot drilling function on the Festool drill countersink BSTA HS D 4.5 CE, item 492524. Model Number: 494446. If your existing countersink setup is still doing the job but the bit is worn, this is the part that makes more sense than replacing the whole assembly.

Festool sells this as a five-piece replacement bit pack, which is the practical move for anyone doing repetitive drilling and countersinking work. Instead of stopping a job because one bit is worn or damaged, you have matching replacements ready to go. For cabinet work, trim installation, and other finish-focused fastening, that kind of consistency matters because the pilot hole size affects screw fit, countersink quality, and the finished look.

The 3/16" (4.5 mm) diameter, listed as 3/16 inch, is the key spec here. It is sized specifically for the matching countersink setup, so the value is not just the diameter by itself but the fact that it preserves the intended performance of the original Festool accessory. The straight shank and spiral flute design keep it in familiar territory for users who want a clean replacement rather than a workaround.

Material matters on small replacement parts, and this bit is listed as High Speed Steel. That is important because a replacement bit needs to hold an edge and stay useful through repeated drilling cycles. It also has sharpened flutes, a spur-less design, and beveled chamfers intended to keep entry and exit holes cleaner while reducing heat buildup. On real work, that translates to smoother drilling and less fuss when appearance counts.

This is not a general-purpose assortment bit and it is not the right buy if you are just looking for a random 4.5 mm drill bit. The point of the Festool 494446 Replacement Drill Bit is system-specific replacement. If you own Festool countersink 492524, this is the correct accessory to keep that tool working the way it was designed to. If you do not own that countersink, compatibility should be checked before buying.

Who is this for? It is best suited to woodworkers, finish carpenters, cabinet installers, and other users who already rely on the Festool countersink setup for repeatable pilot holes and clean screw seating. If you are invested in that accessory and want the right replacement instead of trial-and-error substitutions, this is the straightforward choice.

Festool 494446 Replacement Drill Bit keeps a good countersink in service

The Festool 494446 Replacement Drill Bit is the right buy for users who already own the matching Festool countersink and want factory-correct replacements instead of making a near-fit bit work.

• Who it's for: Woodworkers, finish carpenters, and installers running Festool countersink 492524 for repeat pilot drilling and countersinking.
• Why it stands out: It is a purpose-built 3/16" (4.5 mm) High Speed Steel replacement in a five-pack, so you keep the original setup working the way it should.
• Worth knowing: This is a replacement part, not a universal drill bit kit. Buy it because you need the correct bit for Festool 492524, not because the diameter looks close enough for something else.

• What is this bit made for? It is made as a replacement bit for the Festool drill countersink BSTA HS D 4.5 CE, item 492524.
• What size is the bit? The bit diameter is 3/16" (4.5 mm).
• How many bits are included? This pack includes five replacement bits.
• What material is it made from? The bit is listed as High Speed Steel, also called HSS.