35mm Billet 12AN Turbo Drain Oil Flange

Stop fighting undersized drain ports and sloppy castings. This 35mm billet 12AN turbo drain flange is machined to do the job right, the first time.

Features & Benefits

Billet Construction, Not Cast

Machined from billet aluminium for superior strength, crack resistance, and a precision sealing surface that castings simply can't match. No porosity, no surprises.

Built for Mid-Frame & Large-Frame Turbos

Machined to the bolt centre found on common mid-frame and large-frame turbochargers — 50mm (1.97") on mid frame and 50.8mm (2.00") on large frame — making it a straightforward fit on platforms such as the S300, S400, and HX40, journal bearing or ball bearing. Bolt centre is measured from the centre of one drain pad bolt hole to the centre of the other.

35mm (1.38") Drain Length

The 35mm figure is the length of the drain — how far the drain body stands off the flange face before your hose connects. This is the shortest of the three lengths we offer, keeping the assembly compact and tucked in tight where clearance around the drain pad is not a problem. Also available in 65mm (2.56") and 100mm (3.94") when you need more reach.

12AN Port for High-Volume Oil Return

Larger-frame turbos flow more oil and need a drain that keeps up. The 12AN port pairs directly with a 12AN braided stainless drain line for a clean, high-flow return that won't back up oil into your seals.

Precision-Machined Sealing Surface

Every face is machined flat so your gasket seals properly and stays sealed, helping you avoid chasing leaks after the build is done.

Made by BSI Inc.

Manufactured by Black Sheep Industries right here in Canada, with CAD pricing and shipping across North America. You're getting a part built to a standard, not a price.

Whether you're assembling a fresh turbo build, replacing a tired factory drain flange, or upgrading to a proper AN drain line, this flange gives you a reliable, leak-free foundation from day one.

Not sure which drain you need? See the S400 Turbo Oil Drain Guide for bolt centre measurement, length selection, and full sizing charts in metric and US standard.

FAQ

What turbochargers is this flange built for?

It is built for common mid-frame and large-frame turbochargers — a 50mm (1.97") bolt centre on mid frame and 50.8mm (2.00") on large frame — including S300, S400, HX40, or similar platforms.

What does the 35mm refer to?

35mm (1.38") is the length of the drain, meaning how far the drain body stands off the flange face. It is the shortest option and suits installs where nothing obstructs the drain pad. It is not the bolt centre or the port size.

What is bolt centre?

Bolt centre is the distance from the centre of one bolt hole to the centre of the other on your turbo's oil drain pad. It identifies the frame class: 38mm (1.50") small frame, 50mm (1.97") mid frame, 50.8mm (2.00") large frame. Measure with calipers, as mid and large frame sit only about 1/32" apart.

What oil drain line size does this flange use?

This flange uses a 12AN port designed to pair directly with a 12AN braided stainless drain line.

Why is billet aluminium construction used?

Billet aluminium provides superior strength, crack resistance, and a precision sealing surface compared with castings.

Where is this turbo drain flange made?

It is manufactured by Black Sheep Industries in Canada, with CAD pricing and shipping across North America.