rashid111 writes:

What is a difference between SCFM and CFM?

From my page at http://www.truetex.com/aircompressors.htm :

An "SCFM" (standard cubic foot per minute) is a CFM produced with input air
at 68 deg F, 36 percent RH, and 14.7 psia pressure (the mere letters
"SCFM" refer to no official standard, and while various temperature and RH
values are in use, these are the most commonly accepted values).
"Displacment CFM" is the rate of volume displaced by a reciprocating piston
compressor, which is compared to the delivered CFM to evaluate volumetric
efficiency. "Peak horsepower" typically means the electrical power drawn by
the motor at the instant of starting; this figure is a meaningless
specification because it says next to nothing about the sustainable
horsepower delivered by the system. "Peak horsepower" most definitely does
not mean anything like "what you get if you run this unit full throttle",
"what the motor can deliver for short periods of time", or "what the motor
can do if heavily loaded". Also, rated CFM at "90 psi" can really mean the
inflated value measured from the CFM input during a pump-up from 0 to 90
psi. This is what you get in the absence of well-defined engineering
testing standards and methods, which is to say, "consumer" mentality.