Honda 10 mm flange nut 90212-SA5-003

Honda 90212-SA5-003 flange nut 10 mm

Genuine Honda 10 mm flange nut, part number 90212-SA5-003. Commonly used on exhaust joints to provide a secure, vibration-resistant connection. This nut supersedes part numbers 90212-SP0-000 and 90212-671-005.

Supplied in bulk bags of 10 pieces. Single nuts are shipped loose, without the original bag.

Applications – exhaust system joints

Although this flange nut is very universal and appears in many Honda models from the 1980s up to current cars, in practice it is most often used for:

• joining sections of the exhaust system (pipes, mufflers, catalytic converters),
• fastening exhaust flanges and clamps,
• connections around flex joints and centre sections,
• various mounting points where Honda specifies an M10 flange nut.

Note: this nut should not be used to fasten the exhaust manifold to the cylinder head. For manifold studs Honda usually uses an 8 mm flange nut – available here: Honda flange nut 8 mm 94050-08080 .

Why replace the nuts with new ones?

• old exhaust nuts are usually corroded and heat-affected,
• a fresh flange nut clamps the flanges better and helps to prevent exhaust leaks,
• new hardware makes future disassembly easier (less risk of seized fasteners),
• genuine Honda hardware guarantees correct thread, height and flange diameter.

FAQ – Honda 90212-SA5-003 flange nut

Will this nut fit my Honda?
The nut is used on many different models. The safest way is to check fitment by VIN – send it to us and we will confirm compatibility free of charge before you order.

How is it different from the 8 mm manifold nut?
Part 90212-SA5-003 is an M10 flange nut used mainly on exhaust flanges. Manifold studs in the cylinder head usually take an M8 flange nut (94050-08080), designed specifically for that application.

Can I reuse the old nuts?
Sometimes you can, but it is not recommended. Heat and corrosion weaken the material. A new set of nuts is cheap compared to the labour cost of removing the exhaust again if a joint starts leaking.

Why is there no detailed vehicle list?
This nut is used across dozens of different models and variants. Instead of an incomplete list we prefer to verify directly by VIN, so you know you are buying the correct part.