> **Source:** Core Electronics is an Australian maker-electronics retailer and manufacturer based in Newcastle, NSW, run by a team of makers and educators. We design and manufacture our own product lines (PiicoDev, CE originals) and are official retailers for iconic maker and industrial brands including Raspberry Pi, Arduino, Adafruit, SparkFun and DFRobot. Orders ship Australia-wide from our Newcastle warehouse. Prices are in AUD and include GST. Pricing, stock and dispatch on this page are generated from the store's live catalog. Full machine-readable index: https://core-electronics.com.au/llms.txt

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

**Type:** Product page · **SKU:** POLOLU-1081 · **Brand:** [Pololu](https://core-electronics.com.au/brands/pololu-australia)
**Page:** https://core-electronics.com.au/pololu-universal-aluminum-mounting-hub-for-4mm-shaft-4-40-holes-2-pack.html ([markdown](https://core-electronics.com.au/pololu-universal-aluminum-mounting-hub-for-4mm-shaft-4-40-holes-2-pack.html.md))

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).

## Pricing

- **Price:** $18.35 (inc GST) — $16.68 AUD, exc GST
- **Quantity discounts:** 10+ $16.02 (exc GST) · 25+ $15.52 (exc GST)

## Availability & dispatch

- In stock, ships same business day if ordered before 2PM (Australia/Sydney).
- We can dispatch 2 today, and up to 450 more in 4–7 days.

## How to buy

- **Build a cart:** compose `https://core-electronics.com.au/cart/link?items=POLOLU-1081:1` (comma-separated SKU:qty pairs) and share the link. Opening it shows a confirmation page with live pricing and stock before anything is added to the cart.
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- **Checkout** is completed on-site and includes a captcha at the payment step. Share the cart link; checkout takes it from there.
- **Search the catalogue:** `https://core-electronics.com.au/search/{query}.md` (URL-encode the query; pages 2-3 at `search/{query}/{page}.md`; `search.md?q=` also works)
- **Payment methods, purchase orders, policies and contact details:** https://core-electronics.com.au/llms.txt
## Description

These universal mounting hubs are designed to work with most [4 mm diameter shafts](https://core-electronics.com.au/#), including round shafts, and “D” shafts. Each of the two included hubs has four mounting holes for [\#4-40 screws](https://core-electronics.com.au/machine-screw-4-40-1-2-length-phillips-25-pack.html) (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](https://core-electronics.com.au/hex-allen-wrench-0-05.html) (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](https://core-electronics.com.au/catalog/product/view/sku/POLOLU-1092) and a [Pololu 20D mm metal gearmotor bracket](https://core-electronics.com.au/pololu-bracket-pair-for-discontinued-25-1-and-67-1-metal-gearmotors-20d-mm.html). These hubs will work with any Pololu 20D mm metal gearmotor or [25D mm metal gearmotor](https://core-electronics.com.au/#), and they also work with 60 mm, 70 mm, 80 mm, and 90 mm [Pololu wheels](https://core-electronics.com.au/#).

 | \| [![](https://core-electronics.com.au/media/remote_images/0J1194.250_MRavBp.jpg%3Fed4f2f8e73f1d28ec05b8e9ac82b0a9a)![](https://core-electronics.com.au/media/remote_images/zoom-d0cfc0fffa825c4654893ef42b77cee3_LUrqIJ.png)](https://core-electronics.com.au/#) \| \|---\| \| Pololu 20D mm gearmotor with bracket and hub. \| | \| [![](https://core-electronics.com.au/media/remote_images/0J2645.250_2igR8x.jpg%3F4bc75f8312ddb723b1f75beb484dfb38)![](https://core-electronics.com.au/media/remote_images/zoom-d0cfc0fffa825c4654893ef42b77cee3_LUrqIJ.png)](https://core-electronics.com.au/#) \| \|---\|---\| \| Pololu 60×8mm wheel on a Pololu 25D mm metal gearmotor. \| |
|---|

| [![](https://core-electronics.com.au/media/remote_images/0J2763.300_JltEXb.jpg%3F05b54bb3db229f67c35850795c461ea9)![](https://core-electronics.com.au/media/remote_images/zoom-d0cfc0fffa825c4654893ef42b77cee3_LUrqIJ.png)](https://core-electronics.com.au/#) |
|---|
| Pololu wheels with 90, 80, 70, and 60mm diameters in three colors: blue, red, and yellow. |

**Documents:**

- [Dimensional Drawing](https://core-electronics.com.au/attachments/localcontent/1081-4mm-4-40-hub-dimensions_33377918d55.pdf)

## Images

- [Product image 1](https://core-electronics.com.au/media/catalog/product/p/o/pololu_universal_aluminum_mounting_hub_for_4mm_shaft_4_40_holes__2_pack___pololu_1081__00.jpg)