Key takeaways
- A framing nailer's air figure is per nail, not per minute. DeWalt prints 0.072 at 100 psi and labels it CFM, Metabo HPT prints .088 ft3/cycle at 100 psi, and its product page rounds that to 0.09 scfm.
- Metabo HPT and Paslode print the same sizing formula. Number of tools times nails per minute times air per nail times a 1.2 safety factor gives the CFM the compressor must supply.
- At 30 nails a minute, the rate both makers use in their worked examples, four framing nailers need 2.6 to 3.3 CFM with the safety factor, depending on brand and pressure.
- A 2.2 CFM at 90 psi pump keeps up with about 22 to 24 nails a minute on that formula, and a 5.3 CFM pump with about 54 to 59. A tank only adds a burst on top.
- Air per nail rises with pressure. Metabo HPT's table goes from .062 at 80 psi to .088 at 100 psi, 42 percent more air for 20 psi.
Two answers circulate, and neither comes from a nailer maker. One says a framing nailer needs about 2 to 2.5 CFM at 90 psi. The other says 4 to 5. Both are ranges with no arithmetic behind them, and both are right for some pace of work and wrong for another, because a framing nailer has no fixed CFM. It uses a fixed amount of air per nail, and the CFM is whatever that comes to at your nailing rate.
The confusion starts on the spec sheets. DeWalt prints its D51823's air figure as ".072@100PSI" under a heading of CFM. Metabo HPT's product page lists the NR90AES1 at "0.09 scfm". Read as flow, those numbers say a framing nailer runs on a tenth of a CFM, which no compressor is small enough to match. Both are cubic feet per nail.
What the makers actually print
Four framing nailers, with the air figure exactly as each maker labels it and converted to one unit:
| Nailer | Collation | Air figure, as printed | At | Cubic feet per nail | Litres per nail | Operating range |
|---|---|---|---|---|---|---|
| DeWalt D51823 | Clipped head | .072, under "CFM" | 100 psi | 0.072 | 2.04 | 70 to 120 psi |
| Metabo HPT NR90AES1 | 21 degree plastic | .088 ft3/cycle (manual), 0.09 scfm (web) | 100 psi | 0.088 | 2.5 | 70 to 120 psi |
| Paslode F-350S | 30 degree | .082 SCFM per fastener, chart | 90 psi | 0.082 | 2.32 | 80 to 120 psi |
| Bostitch F21PL-E | 21 degree plastic | 2.47 litres per shot | 5.6 bar (81 psi) | 0.087 | 2.47 | 4.8 to 8.3 bar (70 to 120 psi) |
There are 28.32 litres in a cubic foot, so Bostitch's 2.47 litres is 2.47 / 28.32 = 0.087 cu ft. Metabo HPT's manual prints the litre figure itself, 2.5 litres per cycle at 6.9 bar.
Only Bostitch and Metabo HPT's manual name the unit as per shot or per cycle. Paslode's chart is headed "AIR CONSUMPTION-SCFM FASTENER", standard cubic feet per fastener. DeWalt's service page and Metabo HPT's web page put the per-nail figure under a per-minute unit. None of the four documents states how the figure was measured, so compare them as each maker's own rating, not as results from one test.
The figures also sit at three different pressures, which matters more than the brand, as the next table shows.
Air per nail rises with pressure
Two makers publish more than one pressure. Metabo HPT's manual prints an air consumption table, and Paslode's prints a chart with a line across its operating range:
| Pressure | Metabo HPT NR90AE(S1), table | Paslode F-350S, read from chart |
|---|---|---|
| 70 psi | not listed | about 0.065 |
| 80 psi | 0.062 (1.7 litres) | about 0.074 |
| 90 psi | 0.075 (2.1 litres) | 0.082, marked |
| 100 psi | 0.088 (2.5 litres) | about 0.092 |
From 80 to 100 psi, Metabo HPT's figure rises from .062 to .088, 42 percent more air per nail for a 20 psi turn of the regulator. Paslode's line rises about 24 percent over the same span. So two things follow. First, compare nailers at the same pressure: DeWalt's .072 and Metabo HPT's .088 are both at 100 psi, but Paslode's .082 is at 90 and Bostitch's .087 is at 81. Second, the cheapest air you can buy is the regulator setting. Paslode says its tools "are designed to operate efficiently between 90 and 120 psi", and every maker here allows 70 or 80 at the bottom. The lowest pressure that sets the nail flush is the one to run.
The formula two makers print
Metabo HPT and Paslode both print a compressor sizing formula in their manuals, and they are the same formula:
CFM required = number of nailers x nails per minute per nailer x air per nail x 1.2
Metabo HPT calls the 1.2 a "safety factor (always 1.2)". Paslode uses the same 1.2. Metabo HPT's worked example is two nailers at 100 psi driving 30 nails a minute each: 2 x 30 x .088 x 1.2 = 6.3 CFM, printed as 180 litres a minute. Paslode's example is a production line of 10 tools at 30 fasteners a minute, using a tool rated at 0.051 scfm per fastener: 10 x 30 x 1.2 x 0.051 = 18.36 scfm.
Neither manual sets a nailing rate. Both say to use the average nails driven each minute by each tool, and both worked examples happen to use 30. That is the variable you supply, and it is the reason a single CFM figure for "a framing nailer" cannot be right.
Here is the formula run for each nailer at its published pressure:
| Nailer and pressure | 10 nails/min | 20 nails/min | 30 nails/min | 45 nails/min | 60 nails/min |
|---|---|---|---|---|---|
| DeWalt D51823, 100 psi | 0.9 CFM | 1.7 CFM | 2.6 CFM | 3.9 CFM | 5.2 CFM |
| Metabo HPT NR90AES1, 100 psi | 1.1 CFM | 2.1 CFM | 3.2 CFM | 4.8 CFM | 6.3 CFM |
| Metabo HPT NR90AES1, 90 psi | 0.9 CFM | 1.8 CFM | 2.7 CFM | 4.1 CFM | 5.4 CFM |
| Paslode F-350S, 90 psi | 1.0 CFM | 2.0 CFM | 3.0 CFM | 4.4 CFM | 5.9 CFM |
| Bostitch F21PL-E, 81 psi | 1.0 CFM | 2.1 CFM | 3.1 CFM | 4.7 CFM | 6.3 CFM |
All figures include the 1.2 factor. Worked for the Paslode at 30 nails a minute: 30 x 0.082 x 1.2 = 2.95, rounded to 3.0. Drop the 1.2 and every figure falls by a sixth, so the Metabo HPT at 30 a minute and 100 psi needs 2.64 CFM before the margin.
That table explains both circulating answers. The "2 to 2.5 CFM" figure is one nailer at a bit over 20 nails a minute, or 30 a minute without the safety factor. The "4 to 5 CFM" figure is one nailer at about 45 a minute, or most of the way to two nailers at 30. Neither is wrong; each describes a different pace of work.
How many nails a minute a compressor can keep up with
Turn the formula around and a compressor's rating becomes a nailing rate, which is easier to judge against your own work than a CFM:
sustained nails per minute = pump CFM / (air per nail x 1.2)
Compressor ratings are stated at 90 psi, so the fair pairing uses air per nail at 90 psi, which Metabo HPT and Paslode both publish. These are the same three compressors worked through for tank size in whether a bigger compressor tank gives you more CFM:
| Compressor | Pump rating at 90 psi | Metabo HPT at 90 psi (0.075) | Paslode at 90 psi (0.082) |
|---|---|---|---|
| California Air Tools 8010, 8 gal, 1.0 HP | 2.20 CFM | about 24 nails/min | about 22 nails/min |
| DeWalt DWFP55126, 6 gal pancake | 2.6 SCFM | about 29 nails/min | about 26 nails/min |
| California Air Tools 10020C, 10 gal, 2.0 HP | 5.30 CFM | about 59 nails/min | about 54 nails/min |
Worked for the 8010 and the Metabo HPT: 2.20 / (0.075 x 1.2) = 24.4 nails a minute. Without the safety factor it is 29.
So a 1 HP pump that makes about 2.2 to 2.6 CFM keeps one framing nailer going at roughly the 30 nails a minute both makers use as their example, a little under it with the margin and a little over without. A 2 HP, 5.3 CFM pump covers one nailer at nearly double that pace. It does not quite cover Metabo HPT's own two-nailer example: that needs 6.3 CFM at 100 psi, or 5.4 CFM if both nailers run at 90 psi, and the 10020C is rated 5.30 at 90.
Paslode's manual adds a rule of thumb: "in compressors approximately 1 hp is required to produce 4 scfm". The small compressors here fall well short of it. California Air Tools rates its 1.0 HP 8010 at 2.20 CFM at 90 psi and its 2.0 HP 10020C at 5.30, about 2.2 to 2.65 CFM per rated horsepower. Use the CFM at 90 psi on the compressor's own page, not its horsepower.
What the tank adds: a burst, then the pump's rate
A tank lets you nail faster than the pump for a while. How long follows from the stored air worked out in the tank guide, the free air between a full tank and 90 psi, divided by air per nail at 90 psi:
| Compressor | Free air above 90 psi, full tank | Nails stored, Metabo HPT (0.075) | Nails stored, Paslode (0.082) |
|---|---|---|---|
| California Air Tools 8010, 8 gal at 120 psi | 2.2 cu ft | about 29 | about 27 |
| California Air Tools 10020C, 10 gal at 125 psi | 3.2 cu ft | about 42 | about 39 |
| DeWalt DWFP55126, 6 gal at 165 psi | 4.1 cu ft | about 55 | about 50 |
The smallest tank holds the most nails because it is filled 40 to 45 psi higher, the same point the tank guide makes in cubic feet.
Put the burst and the pump together for a run of sheathing at 60 nails a minute on the Metabo HPT at 90 psi. That pace draws 60 x 0.075 = 4.5 CFM, before any margin. On the 8010 the shortfall is 4.5 - 2.2 = 2.3 CFM, and the stored 2.2 cubic feet lasts about a minute, roughly 57 nails, before the nailer is down to the pump's 29 a minute. On the DeWalt pancake the shortfall is 1.9 CFM and the stored air lasts about two minutes, roughly 129 nails. On the 10020C the pump makes more than the nailer draws, so the tank never runs down at that pace.
The tank choice changes how long a fast burst lasts. The pump choice changes what you can keep up all day. For framing, where the work comes in bursts with layout and cutting between them, a small pump with a high-pressure tank often keeps up, and the arithmetic above tells you how fast you can go before it does not.
Hose and fittings for a framing nailer
At the flows in this article, hose is rarely the limit. On the industry chart read in the air hose guide for impact wrenches, 50 ft of 3/8 in hose loses about 1.3 psi at 6.2 CFM, about what two framing nailers at 30 nails a minute need on the makers' formula. None of the four makers publishes the flow during a single drive, which is higher than the average, so do not size a long run of 1/4 in hose on these averages. Metabo HPT's manual lists a 3/8 NPT inlet on the NR90AE(S1), and Paslode says that "for optimum performance" it recommends a 3/8 in male fitting on the F-350S. Both point to 3/8 in fittings and hose, not 1/4 in.
A 50 ft framing hose and a reel are bulky, low-frequency items, the kind that belong on a wall rather than the floor; the wall storage comparison covers which wall systems carry that kind of load.
Where this answer stops applying
- Your nailing rate is the estimate. The makers print air per nail. They do not print how fast anyone frames. 30 a minute is the rate both manuals use in their examples, not a measurement of framing work. Count your own pace for a few minutes and put it in the formula.
- Compressor output at 100 psi. Compressor makers here rate at 90 psi. California Air Tools' pump makes 3.10 CFM at 40 psi and 2.20 at 90, so output falls as pressure rises, and at 100 psi it will be lower than the 90 psi figure by an amount none of these pages gives. Running the nailer at 90 psi keeps both figures on one basis.
- Brands without a pressure table. DeWalt prints one point at 100 psi and Bostitch one at 5.6 bar. Their air at other pressures is not published, and this page does not convert it. The Metabo HPT and Paslode tables show the change can be 24 to 42 percent over 80 to 100 psi, so the brands are only directly comparable at a shared pressure.
- Other nailers. These are full-size framing nailers driving nails up to 3-1/2 in (90 mm). A finish, siding or roofing nailer has its own per-shot figure. Look up the tool's own per-shot figure; the formula is the same.
- The regulator and hose need headroom. The stored-nail counts assume the tank can be drawn to exactly 90 psi with the regulator still delivering 90. In practice it needs a margin above its setting, so the burst is somewhat shorter, as the tank guide explains.
Placing and powering the compressor
A compressor that keeps up with two framing nailers is a 2 HP class machine; California Air Tools lists the 10020C at 14 A. That is close to a full 15 A circuit on its own, which is why the garage shop layout guide advises leaving a dedicated circuit for a compressor, and why the extension cord gauge guide leaves compressors to their own manual's cord instructions rather than its tool tables.
If the numbers say you need more pump than you have room or power for, a cordless framing nailer avoids the calculation entirely. Compare cordless packs on watt hours rather than the voltage on the label, as worked out in whether 20V MAX is the same as 18V.
The thirty-second check
- Find the nailer's air figure. If it is between about 0.06 and 0.10, it is cubic feet per nail whatever unit it is printed under. Note the pressure it is stated at.
- Estimate your nails per minute. 30 is the makers' example rate for one nailer.
- Multiply: nailers x nails per minute x air per nail x 1.2. One nailer at 30 a minute needs about 2.6 to 3.3 CFM.
- Compare that with the compressor's CFM at 90 psi, not its horsepower or tank size. If the pump is lower, divide pump CFM by air per nail x 1.2 for the pace it does sustain.
- If you work in bursts faster than that, divide the tank's free air above 90 psi by air per nail to see how many nails the burst covers, then turn the regulator down to the lowest pressure that sets the nail.