Speed Nipple Bit 1.5mm

The 1.5 mm Speed Nipple Bit is the shorter-pin of the two cordless-driver bits in the Unior wheelbuilding line. Where the 2.5 mm bit uses the longer 2.5 mm depth pin, this one uses the shorter 1.5 mm pin. Both drive the same conventional slot-head internal spoke nipples; the number is the length of the depth-control pin, not a nipple size. The shorter pin lets each nipple thread further down its spoke before the driver unseats, so the nipples finish closer to tension.

Same depth-control principle as the 2.5 mm bit: a small nub machined into the tip of the bit keeps the driver centered in the recess and controls how far the nipple threads down the spoke. When the nub touches the approaching spoke, the bit unseats; every nipple ends up at the same starting depth, which is the precondition for an even tensioning pass on the rest of the build.

If you want the nipples threaded to a shallower starting depth so a drill won't over-tension them, the Speed Nipple Bit 2.5mm is the longer-pin option instead. Choose between the two by how far your spokes thread into the nipples; both drive the same conventional slot-head nipples and leave every nipple at the same starting depth, ready for the tensioning pass.

Compatibility

• Nipples: any conventional slot-head (screwdriver-slot) internal spoke nipple.
• Drive: 1/4" hex shank.
• Wheels: any wheelset with standard slot-head nipples.
• Companion: Speed Nipple Bit 2.5mm with the longer 2.5 mm depth pin, for a shallower thread-down.

Specs

• Tip: slot-head, with a 1.5 mm depth-control pin machined into the center.
• Drive: 1/4" hex shank.
• Compatible with cordless screwdrivers, drill drivers, and impact drivers.

Built in Zreče, Slovenia

Unior has been forging hand tools in Zreče since 1919. The 1.5 mm speed bit is the one to reach for when you want the nipples threaded deeper, closer to tension, straight off the driver. Plenty of workshops keep both pin lengths in the drawer so they can match the bit to how each set of spokes threads into its nipples.

Pro tip from our mechanics

Set the bit in the nipple and give it a half-turn by hand to feel the engagement before you bring the driver into play. If the bit is going to walk off, it will walk off in that first half-turn; better to feel it then than to discover it after a few rotations under driver power. The full wheel-building workflow is in How to true a bike wheel →

FAQ

Which spoke nipples does the 1.5 mm Speed Nipple Bit fit? The same conventional slot-head (screwdriver-slot) internal spoke nipples as the 2.5 mm version. The 1.5 mm and 2.5 mm are not different nipple sizes; they are the length of the depth-control pin. So this bit fits any standard slot-head nipple, and you choose the pin length by how far your spokes thread into the nipples, not by the nipple's slot. It does not fit square-drive or internal-hex nipples, which need a matching bit.

What is the difference between the 1.5 mm and 2.5 mm bits? Only the length of the depth-control pin, which sets how far each nipple threads down its spoke before the driver unseats. The shorter 1.5 mm pin lets the nipple thread deeper, so it finishes closer to tension. The longer 2.5 mm pin stops the nipple at a shallower depth, so a drill will not over-tension it. Pick the one that matches how far your spokes thread into your nipples, or keep both on the bench for different builds.

Do I still need a manual nipple driver, or does this replace it? The speed bit is for high-volume building, where a cordless driver threads all the nipples in two or three minutes instead of the ten or fifteen a screwdriver takes. If you build a wheel or two a season, a manual nipple driver is plenty. If you build a wheel a week or run a busy shop, the speed bit pays for itself in saved time on the first few wheels.

How should I run it on a cordless driver? Start each nipple at low speed for the first quarter-turn, then switch to high speed once it is engaged. Setting the bit in the nipple and feeling the engagement with a half-turn by hand first helps, since that is when a bit walks off if it is going to. The 1/4" hex shank fits any standard cordless screwdriver or drill driver; run it as a drill, not in hammer or impact mode. Remember the bit only threads nipples to a starting depth; final tension is set with a spoke wrench.