By Tim Uhler
When Bosch introduced its first line of pneumatic nailers last spring, it claimed that the tools were 20 percent smaller and 10 percent more powerful than the competition. It was an assertion I kept in mind when I tested the company's 20-degree stick gun. (The line also includes a 34-degree clipped-head nailer, a roofing nailer, trim guns, and a narrow-crown stapler.) Here's what I found out after a couple of months of using the SN350-20F on my framing jobs.
Bosch SN350-20F Specs
Weight: 8.4 pounds
Dimensions (H x L): 13.6 inches by 21.4 inches
Nail length: 2 to 31/2 inches
Nail diameter: .113 to .148 inch
Made in: Taiwan
A similar model is available for use with 34-degree clipped-head nails.
Most nail guns have multiple chambers — a large cylinder that contains the piston and driver, plus small side chambers. When the trigger is depressed, a blast of compressed air enters the large chamber and slams the piston down, causing the driver to strike the nail. On its way down, the piston forces air into the side chambers; it is this compressed air that pushes the piston back to the starting position after the nail is driven. According to Bosch, about 10 percent of the air pressure that enters the cylinder in most guns is used to return the piston — which means only 90 percent actually drives the fastener.
The Bosch guns rely on a different mechanism to return the piston. They have no side chambers. Instead, a valve feeds a second blast of air into the bottom of the cylinder, pushing the piston back to the starting position. That way, says Bosch, 100 percent of the force from the initial blast of air is transferred to the fastener. The manufacturer refers to this design as "full force technology" and says it gives the guns superior power.
Size and Performance
The SN350-20F is, as advertised, smaller than other framers. Although it's not any shorter top-to-bottom or end-to-end, it has a much slimmer piston housing. I attribute this to the absence of side chambers. Smaller is often better, but for a framing gun the diameter of the housing is not a critical dimension.
Whether the tool is 10 percent more powerful than competing models is a little harder to judge. On my jobs it drove nails very well into engineered wood, doing a marginally better job than an older model, Hitachi's NR83A2. Like all guns, it sometimes leaves fasteners proud in engineered lumber — but less often than most. And it had no trouble driving nails of up to .148 inch. While it felt a little slower than the guns I normally use, the difference was too subtle to cause problems.
At 8.4 pounds, the Bosch is heavier than the average stick nailer. However, it's so well-balanced it doesn't feel heavy. It cushions the blow well, a trait I appreciated. Long periods of bounce-nailing with a lighter gun can leave you with a sore wrist, but that's less likely to happen with this nailer. The framer's firing mode is controlled by a switch on the back of a large, comfortable trigger (left). Jams can be cleared by pivoting a lever (right) and pulling back on the magazine.
The SN350-20F has most of the features commonly found on framing guns. It has a very aggressive nosepiece for improved toenailing and a knob-operated toolless depth-of-drive mechanism. I wish it came with a rafter hook; instead, the hook is a $20 accessory.
The magazine can be removed with the flip of a lever — a nice touch that makes clearing jambs quick and easy. To load the tool, you pull back on the follower until it clicks to a stop, drop in fasteners, then pull again until the follower pops free and slides forward. The oversize trigger is comfortable to operate and has a switch for changing between bounce and sequential firing mode.
It's a pretty rugged tool: The trigger and rubberized grip are the only plastic components. A built-in air filter prevents dirt and grit from getting inside, which should prolong the tool's life. A metal plate on top of the piston housing will protect the gun if you use it to tap framing into position. The downside to this design is that the direction of the exhaust is not adjustable.
The SN350-20F is well-balanced, does a good job cushioning recoil, and can handle any framing task a carpenter would need it to do. It's marginally more powerful than the stick framer I normally use, though not enough to make a difference. I haven't had it long enough to know how durable it is, but it looks and feels well-made.
My recommendation? If you don't mind using a gun that is slightly heavier than average, this one is worth considering.
Tim Uhler is a lead framer for Pioneer Builders in Port Orchard, Wash., and a JLC contributing editor.
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