The Castair Replacement Axle Bolt for 20-Gallon Portable (AB34) is the OEM replacement wheel axle bolt for Cast Air 20-gallon portable compressor tanks. At $5.39, this is the 3/4" bolt that keeps the wheels attached to a tank that weighs significantly more than the 8-gallon units. A 20-gallon portable is heavy enough that losing wheel mobility is a real problem -- dragging it across a shop floor without wheels is not practical, and using an incorrect substitute bolt that shears under load is worse.
The step up from 1/2" to 3/4" between the AB12 and AB34 is not arbitrary. The 20-gallon portable tank carries substantially more weight, and the axle hardware is sized accordingly. Using the wrong bolt -- even one that fits the hole -- puts the wrong load on undersized hardware. Get the correct OEM part.
Key Features
- OEM Cast Air part: Exact fit for 20-gallon portable compressor tank wheel axles -- correct diameter, thread, length, and head specification
- Correct 3/4" diameter: Sized for the heavier load a 20-gallon portable puts on the axle hardware; larger than the 1/2" AB12 used on 8-gallon portables
- Direct replacement: Installs as the factory original -- no modification, no thread chasing, no adaptation
- Right grade for the application: OEM parts are specified for the load they carry; hardware store substitutes are not
- Minnesota-made quality: Cast Air manufactures in Minnesota with consistent specifications across their tank and compressor line
Which Bolt Does Your Tank Take?
Cast Air portable tanks use two different axle bolt sizes. Do not order by hole size alone -- order by tank size:
- AB12 -- 1/2", $3.85: For Cast Air 8-gallon portable air receiver tanks
- AB34 -- 3/4", $5.39: For Cast Air 20-gallon portable air receiver tanks
If your shop runs both sizes, stock one of each. Total cost is $9.24. A grounded portable tank wastes more than $9.24 in tech time the first time it happens.
When Does a Shop Need This
Order the AB34 when:
- The 20-gallon portable has a stripped, sheared, or missing axle bolt and the tank cannot move
- You are servicing or rebuilding a 20-gallon portable tank and replacing worn hardware as part of the job
- You are building a spare parts shelf for Cast Air portable equipment
- A tech has already installed a hardware store substitute and you need to put the correct part back in
Do not order this for 8-gallon portable tanks -- those take the AB12 (1/2"). A 3/4" bolt will not fit the axle bracket on the 8-gallon unit.
Technical Specifications
- Part Number: AB34
- Manufacturer: Cast Air (Castair), Minnesota
- Bolt Diameter: 3/4"
- Application: Cast Air 20-gallon portable air receiver tank wheel axle
- Price: $5.39
- Category: Tank Accessories / Replacement Hardware
- Related Part: AB12 (1/2" for 8-gallon portable tanks)
What Is Included
- One (1) AB34 replacement axle bolt, 3/4" diameter
Why Buy From Air Compressor Factory Direct
We stock Cast Air replacement hardware alongside the full Cast Air compressor and tank lineup because shops need the correct OEM part when something fails -- not a close substitute. Since 2016, we have supplied professional shops with the right components for their compressed air systems. We carry the full Cast Air accessory catalog so you can source tank hardware, manifolds, controls, and complete compressor units from one place.
Free shipping on qualifying orders. Full manufacturer warranty on Cast Air parts. If you are not sure which bolt your tank takes, call before ordering -- we will confirm the right part before anything ships.
Call 866-217-0063 for quick answers and help!
