ABAC AS-5251BM 5 HP Rotary Screw Air Compressor - Base Mount, 125 PSI, 20.3 CFM, 63 dBA

The ABAC AS-5251BM is a 5 HP base mount rotary screw air compressor built for shops that run air continuously rather than in bursts. It delivers 20.3 CFM at a 125 PSI maximum and runs at 63 dBA, quiet enough to sit in the work area instead of a separate compressor room. Base mount means the unit ships without a receiver, so you plumb it into an air tank you already own or size a tank to the job. At 335 lbs in a 32 x 24 x 40 in cabinet it takes about as much floor as a two drawer file cabinet. Choose 230V single-phase (AS-5251BM) or 208-230-460V three-phase (AS-5253BM).

Key specifications

• Models: AS-5251BM (part number 4152044115) and AS-5253BM (part number 4152043883)
• Motor: 5 HP
• Air delivery: 20.3 CFM
• Maximum pressure: 125 PSI
• Noise level: 63 dBA
• Mounting: base mount, no receiver
• Power supply: 230/1/60 or 208-230-460/3/60
• Weight: 335 lbs
• Dimensions: 32 x 24 x 40 in
• Fully integrated aluminum block air end with vertical oil separation technology
• Digital controller with menu driven operation and programmed maintenance
• Brand: ABAC, part of the Atlas Copco group

CFM measured per ISO 1217 Annex C, quoted at 109 PSI for 125 PSI maximum units. Noise measured per ISO 2151:2004 using ISO 9614/2.

Why a screw instead of another piston

A rotary screw is rated for 100 percent duty, so it holds a steady line pressure through a full shift instead of recovering between jobs. That is the reason to move off a piston machine that is cycling hard, running hot and filling the room with noise. The AS-B air end is a fully integrated aluminum block with vertical oil separation, and ABAC pairs it with an energy efficient motor and a digital controller that handles programmed maintenance, so the service schedule is on the panel rather than on a clipboard.

How it compares

Within the AS-B 5 to 20 HP range the pressure, the airflow and the mounting all move independently. The AS-5501BM is the same machine set for 150 PSI, which trades airflow for pressure at 17.4 CFM in the identical 335 lb cabinet. The AS-7.5251BM steps up to 7.5 HP and 30.5 CFM at the same 125 PSI on the same 32 x 24 x 40 in footprint, at 360 lbs and 67 dBA. If you do not already own a receiver, the AS-5251TM puts the same air end on a 71 gallon tank at 485 lbs, and the AS-5251TMD adds an integrated dryer at 571 lbs. Pick on CFM first, then on pressure, then on whether you want the tank and the dryer in the same package.

Typical applications

Automotive service bays, tire shops, small production and fabrication floors, cabinet and woodworking shops, and any operation where a piston compressor is cycling too hard to keep up. At 20.3 CFM it will keep a pair of air ratchets, a sander or a small spray setup fed all day. At 63 dBA it is quiet enough to leave on the shop floor near the point of use, which saves the piping run a separate compressor room would cost.

What to pair it with

Base mount is the starting point for a modular system. Size a receiver to your demand and pipe it downstream of the compressor, then add moisture control if the air goes to paint, tires or anything that hates water. At 20.3 CFM the ABAC COOL 25 refrigerated air dryer is the matching size, and it runs on 115V so it plugs in beside the compressor without new wiring. See the rest of the rotary screw air compressors and the full refrigerated air dryer range. Call us with your tool list and duty cycle and we will confirm receiver sizing, connection sizes and installation clearances before you pipe it in.