Pololu Universal Aluminum Mounting Hub for 4mm Shaft, #4-40 Holes (2-Pack)

Pololu Universal Aluminum Mounting Hub for 4mm Shaft, #4-40 Holes (2-Pack)
Pololu item #: 1081 61 in stock

Price break Unit price (US$)
1 6.95
10 6.12
100 5.21


backorders allowed

These universal aluminum mounting hubs allow you to mount custom wheels and mechanisms to 4 mm diameter motor shafts. The set includes two hubs, two #4-40 set screws for securing the hubs to motor shafts, and one 0.05″ Allen wrench for use with the set screws. Each hub has four threaded mounting holes for #4-40 screws (not included).

We have an assortment of universal mounting hubs available, spanning several shaft sizes and featuring mounting holes threaded for metric or imperial screws:

Select options:
 Description Specs (4) Pictures (3) Resources (1) FAQs (0) On the blog (0) 

These universal mounting hubs are designed to work with most 4 mm diameter shafts, including round shafts, and “D” shafts. Each of the two included hubs has four mounting holes for #4-40 screws (not included), letting you mount custom wheels or mechanisms to your motors. The two included #4-40 hex set screws (one for each hub) allow secure coupling of shaft to hub, and a 0.05″ hex wrench (often the smallest size in SAE Allen wrench sets) is included for use with the set screws. A dimension diagram of the hub is available under the resources tab.

The picture to the right shows a hub with Pololu’s 25:1 metal gearmotor 20Dx44L mm and a Pololu 20D mm metal gearmotor bracket. These hubs will work with any Pololu 20D mm metal gearmotor or 25D mm metal gearmotor, and they also work with 60 mm, 70 mm, 80 mm, and 90 mm Pololu wheels.

Pololu 20D mm gearmotor with bracket and hub.
Pololu 60×8mm wheel on a Pololu 25D mm metal gearmotor.

Pololu wheels with 90, 80, 70, and 60mm diameters in three colors: blue, red, and yellow.

People often buy this product together with:

Pololu 25D mm Metal Gearmotor Bracket Pair Pololu 25D mm Metal Gearmotor Bracket Pair
Machine Screw: #4-40, 1/2" Length, Phillips (25-pack) Machine Screw: #4-40, 1/2" Length, Phillips (25-pack)
Stepper Motor: Bipolar, 200 Steps/Rev, 20×30mm, 3.9V, 0.6 A/Phase Stepper Motor: Bipolar, 200 Steps/Rev, 20×30mm, 3.9V, 0.6 A/Phase