# Kleinn Hex Adapter - 3/8In F NPT to 1/2In M NPT

The Kleinn Model 51238R is a heavy-duty pneumatic hex adapter engineered to provide a secure, leak-free transition between different thread sizes within your high-pressure onboard air system. Featuring a premium, corrosion-resistant brass construction built to withstand demanding automotive environments, this universal component is designed with a 3/8" Female NPT threaded opening on one side and a 1/2" Male NPT threaded end on the other. This compact fitting allows you to easily adapt oversized tank ports or component lines, maximizing plumbing efficiency and ensuring a reliable air path for your air horns and heavy-duty onboard accessories.

-   3/8" F NPT to 1/2" M NPT
-   Brass construction

## Details

- **Price:** 33.48 CAD
- **Vendor:** Kleinn Air Horns
- **Type:** Hardware - Singles

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 33.48 CAD | In stock |

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> Source: [Standard Auto Part](https://www.standardautopart.com/products/kleinn-hex-adapter-3-8in-f-npt-to-1-2in-m-npt)
> Updated: 2026-08-31