ABAC AS-20S503BM 20 HP Rotary Screw Air Compressor - Base Mount, 150 PSI, 78 CFM, 67 dBA

The ABAC AS-20S503BM is a 20 HP rotary screw air compressor built for shops that need a high volume of air at a higher line pressure, all day, without the noise of a reciprocating machine. It delivers 78 CFM at 150 PSI and runs at 67 dBA. This is the base mount version, so it ships without a tank and plumbs into an air receiver you already own or one sized to your demand. Power is 208-230-460V three-phase.

Key specifications

• Model: AS-20S503BM
• Part number: 4152028456
• Motor: 20 HP
• Air delivery: 78 CFM
• Working pressure: 150 PSI
• Noise level: 67 dBA
• Mounting: base mount, no tank
• Power supply: 208-230-460/3/60

Typical applications

Production and fabrication floors, automotive and fleet service bays, tire and truck shops, cabinet and woodworking shops, and any operation running air tools that call for a 150 PSI supply rather than the usual 125. A rotary screw is designed for continuous duty, so it holds a steady line pressure through a full shift instead of recovering between jobs.

Part of the ABAC AS screw range from the Atlas Copco group. The S in AS-20S is the difference worth understanding: against the standard AS-20503BM at the same 20 HP and the same 150 PSI, this machine delivers 78 CFM instead of 54 CFM and runs at 67 dBA instead of 71 dBA. That is roughly 24 CFM more air from the same motor rating, which is what shops reach for when sandblasting, plasma cutting, or several bays running at once are pulling a standard 20 HP unit down. If your tools run fine at 125 PSI, the companion AS-20S253BM gives you 81.9 CFM at that lower pressure instead. Base mount is the starting point for a modular compressed air system: pair it with a receiver sized to your demand, then add a dryer downstream if your air tools or finishing work need moisture control. Note that some ABAC price sheets list this same part number under the code AS-25S503BM.