"Blunt nails cut through; sharp ones pry apart."

 

There is some truth, decking material will not split as easy if the tip of the nail receives a hammer blow but it doesn't make a difference to a typ 2 x 4.

The softer the material the less likely it will split.

 

I always blunt the nail heads. Never had split wood due to nails with this practice.

 

If it splits, its false, else its true.

 

I never thought about it, until the second box of the same nails all had blunt tips, thinner heads, and shallower grooves. What next, fake nails? As if hitting them in backwards would be the next best thing to a screw (false). I got another brand that matched the ones in the first box and took those back. Not to discount the other statements all together, I'd think pre drilling would be best for preventing splits, while the sharp tip could only split a millimeter, since the rest of the nail is the same size (except when they reduce the quality).

 

A finish nail gun almost eliminates splitting. I still hand nail occasionally but wouldn't want to be without my nail guns!

 

A blunted nail point will set up a shearing effect. A sharp point nail sets up a stress between the fibers of the wood. As your first post stated it will pry apart the wood between the fibers.

 

A blunt chisel splits wood. So I think it has less to do with the tip than the over all shape of what's pounded into it. Even when I predrill next to the edge of some boards, the nail being less than a millimeter larger around will split it, and nothing was pryed by the tip. I don't really think a sharp point pryes things apart, it pierces the material, and the edges tapering up to the full diameter follow through. Testing out small nails on thin wood, and pushing them in like thumb tacks, it was the diameter of the nails that either did or didn't split that. Maybe if you think you need a blunt tip, you should use a thinner nail. Or whatever works, that's just my observation.

 

Well, yes nail size and shape will make a difference as well as the wood size. Try nailing the end of a paint stick. It splits nearly every time. But assuming a typical 2, 3, or 4 D penny framing nail and/or a finishing nail and typical 2 x whatever, blunting the end will diminish splitting almost every time. Pre drilling will always help.

 

So in other words this is one of those true or false questions where the answer is "yes."