Square Profile Nipple Driver

A square-head nipple that sits inside the rim needs a square driver, not a slot blade and not a hex spoke wrench. Unior's 1751/2Q is the inverted square nipple driver: one tool for 3.2 mm square-head nipples in the usual orientation and inverted.

Unior's published line is short. The 1751/2Q turns those 3.2 mm square heads. Official copy says the stem reaches deep aero rims as well as ordinary rims. The handle is metal.

This listing is not the 1751/2 slotted nipple driver and not the 1751/2T insertion tool. Those are different articles. 1751/2 starts a slot-head nipple on the spoke. 1751/2T springs a nipple through a double-wall rim. 1751/2Q is the square recess.

Compatibility

• 3.2 mm square-head spoke nipples, usual orientation and inverted
• Deep aero rims and ordinary rims, in Unior's official wording
• Not the 1751/2 slotted driver
• Not the 1751/2T nipple insertion tool

Specs

• Article 1751/2Q, code 623298
• Nipple: 3.2 mm square head
• Tip (a) 3.35 × 3.35 mm
• Working length (C) 80 mm
• Shaft diameter (D) 6.5 mm
• Overall length (L) 180 mm
• Weight 150 g
• Metal handle
• Official page carries Unior's lifetime-warranty and trivalent-chrome profile badges

All listed dimensions are in millimetres and may vary in tolerance. Weight is in grams.

Built in Zreče, Slovenia

Unior has been forging hand tools in Zreče since 1919, and sponsors professional road and mountain-bike race teams. The 1751/2Q is the square-drive tool in that nipple family. The metal handle and the 80 mm working length are the published reasons it can reach a square head at the bottom of a deep aero rim.

Pro tip from our mechanics

Seat the square tip fully in the recess before you add torque. A half-seated tip chews the head, and the next turn is worse. After the nipples are started, true and dish the wheel on a stand. The procedure is in How to true a bike wheel →.

FAQ

What nipples does the 1751/2Q fit? Unior publishes one job: normal and inverted nipples with a 3.2 mm square head. The driver tip itself is 3.35 × 3.35 mm. It is not a slot-head driver (that is 1751/2) and not the 1751/2T insertion tool.

Will it reach through a deep aero rim? Unior's official copy says the stem works on deep aero rims as well as ordinary rims. The published dimension table lists working length C as 80 mm, shaft diameter D as 6.5 mm, and overall length L as 180 mm.

Is this the same as the 1751/2 nipple driver? No. 1751/2 is the slotted nipple driver. 1751/2Q is the inverted square nipple driver for 3.2 mm square heads. 1751/2T is the spring-loaded tool that feeds a nipple through a double-wall rim. Three articles, three jobs.

What are the official dimensions and weight? Code 623298. Tip a 3.35 × 3.35 mm, working length C 80 mm, shaft D 6.5 mm, overall L 180 mm, 150 g. Dimensions are in millimetres and may vary in tolerance. The official spare-parts list for 1751/2Q is empty.