Help me construct a fair test of nails

If you haven&#;t caught some of the various screw vs. nail threads over the last few months, well here is your chance to catch up on the action.

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Last summer I constructed an experiment to test out what I had been hearing over and over, that due to lower shear strength screws could not be used to face nail metal joiners, such as joist hangers for instance.  I devised an experiment, and ran it on a variety of nails and screws.

A few people here disagreed with the results of those tests.  The results were so dramatic that the tests themselves were called into question.  Fair enough.  I would like to run a new battery, but devise them in such a way that they satisfy the critics of my first rounds.

So if you didn&#;t think I ran a good test before, help me create a new test or tests that will evaluate the ability of an individual fastener to hold a metal strap against a shear load.

To get the ball rolling, here is my first proposal, subject to refinement:

Purpose of Test:  To find out how much of a shear load a variety of fasteners can

Materials used:  16ga. Simpson strap, 4×4 minimum board for fasteners over 1.5&#; long, 2×6 for fasteners 1.5&#; or less.  Wood is green Douglas Fir.

Fastening method:  Nails to be evaluated will be driven into the wood so that the head securely holds the metal to the wood.  For primary testing no more than 3 blows will be used to drive in a nail.

A comparison of these results will be made by testing nails driven with a palm nailer and an inexperienced nailer who will use more than 3 blows to sink a nail.  Comparisons will also be made using a variety of screws that will be driven until the head seats the metal strap against the wood.  In these tests, the nails and screws may have a pilot hole drilled, if so it will be documented.

Testing method:  The 16ga. metal strap will be drawn in a direction perpendicular to the fastener until either the fastener breaks, releases from the wood, the wood deforms more than 1/4&#; without releasing the fastener, or the 16ga. metal strap tears.  The approximate load that the failure occurred will be documented.  Each fastener type will be tested 5 times.

Now, is this a fair test of how well an individual fastener handles a shear load from a metal hanger?  If not, how would you change what was laid out above to make the test better?

&#;EDIT&#;

This will be the first test of the new series:

Driven Nail Pullout: 

Purpose of the test is to determine if the method of driving an individual nail has any bearing on its withdrawal capacity. 

Test Materials: 
The standard nail used on this test will be the 16d Duplex nail, so chosen because of its unique ability to be grasped for withdrawal without damaging the nail or wood after the nail has been fully driven.  The wood used in the test will be Green Douglas Fir, the size will be at least 4×4.  Measured moisture content and weight of samples before testing will be recorded.

Variables to be tested: 
Nails driven with hammer in 3-4 blows driven by experienced carpenter
Nails with field flattened points driven with hammer by experienced carpenter
Nails driven with palm nailer
Nails driven with hammer by inexperienced carpenter
Nails driven by palm nailer into prebored pilot holes (sizes to be specified)

Test Apparatus:
Most engineering test machines are designed to provide maximum data and minimal variation.  Here we are really only looking for one bit of data: force required to withdraw a nail sample.  For this, the test will use a simple claw tool, such as a hammer or pry bar to exert the pulling force.  Attached to the puller will be an extension, such as a 2&#; pipe over the handle or attached to the handle.  The force on this machine will be applied by weight.  A bucket will be attached to a set point on the lever.   Water will be used to weight the bucket.  Water will be gradually added to provide a gradual increase of force to the machine.

Procedure:
Sample will be secured in a vertical position, so that the nail sample exits the wood parallel to the ground.  The testing lever will be placed into position so that it hangs in place with the forks of the claw secure against the top duplex head.  At this point a small force is being applied to the sample.  Water is gently added to the bucket by slowly pouring in water from another bucket.  The test will conclude when the sample nail has been withdrawn at least 1.5&#;.

Sampling:
In accordance with recommendations in ASTM D-88 Section 7, there will be 10 tests per variable

&#;END EDIT&#;

If you want to read up on the history of this, here are the links to my two previous tests posts.

First test batch:
http://forums.taunton.com/tp-breaktime/messages?msg=.1

For more information, please visit types of nails construction.

Second test &#; Shearwall
http://forums.taunton.com/n/mb/message.asp?webtag=tp-breaktime&msg=.1

Rebuilding my home in Cypress, CA

Also a CRX fanatic!

Edited 2/22/ 4:39 pm ET by xxPaulCPxx

Like every DIY-er or construction pro before you, your toolbox or shop is probably full of a random assortment of just about every nail in existence. Start your project plan with a quick review of the difference between nails and screws. Once you&#;ve determined you need nails, how do you select the right one from so many options? Follow along as we go through all you need to know about nails.

The Anatomy of a Nail

Nails are pretty simple in their construction, but the details can matter, depending on your project&#;s needs. Here are the three main parts of a nail:

Head: The nail head is typically flat on top and is struck by a hammer. It is the only visible part of the nail once it is hammered into place.

• Flat Head: Flat and large in relation to the nail diameter, or when compared to other head types. They offer an easy target to hit and sink with a hammer, and also leave a clean, flat surface once sunk.
• Round Head: Typically used in general-purpose projects because of their ease of striking with a hammer.
• Checkered Head: To prevent hammer slippage when striking, checkered heads are textured slightly.
• Countersunk Head: Also called &#;cupped&#; heads, they are very small in relation to the diameter of the nail shank, sometimes barely wider than the shank. They can be hammered below the surface of the work surface (aka the act of &#;countersinking&#;) and concealed.

Shank: The nail shank is the skinny part of the nail, which provides the fastening to the object you&#;re hammering into.

• Smooth bright shank: Made of raw, unfinished metal, these are the most common type of nail and are good for many indoor projects. They&#;re not ideal for outdoor projects because they have no anti-corrosion treatments and can rust. Most common smooth nails are made of steel.
• Ring shank: Almost a hybrid of a nail and a screw, ring shanks or annular ring shanks, are nails with a curving ring along the shank. Great when working with softwoods to lock with the wood fibers and provide great holding power. They&#;re often used for decks, roofs, and asphalt shingle installation.
• Barbed/spiral/screw shank: Similar to ring shanks, but with the added fastening power of a twisted shape along the shank. They can be helpful in framing projects in high wind conditions or when hanging siding or clapboard, and when building fencing.
• Fluted or helical shank: A flute or groove on a shank is designed to spin the nail as it&#;s hammered into place. This can also improve the grip of the nail. They are often seen in masonry nails for driving into concrete or steel.

Point: a nail's point is what pierces the wood or other material you&#;re hammering it into.

• Dull point: Duller points can still be driven easily, but won&#;t split delicate wood.
• Blunt point: A blunt point will break the fibers as it&#;s hammered, instead of chiseling through them as a sharp point would do. This can be beneficial when you&#;re aim is not to crack or split the wood you&#;re working with. You can also hit a regular-point nail to &#;blunt it&#; before use. It will be harder to drive, but less likely to split the wood.
• Diamond point: The diamond point nail is one of the sharpest points you can choose. Easy to drive, a diamond point is common to nails you&#;ll find in most nail options. A long diamond point will have minimal chance of splitting the materials it&#;s joining.

Nail Types and When You Need Them

General nail types include:

• Common nails: General-purpose nails are often made of steel and used in general woodworking projects or general construction work.
• Box nails: Narrower in the shank and smaller than common nails, and therefore have less holding power and shouldn&#;t be used for building structures.
• Brad nails: Have smaller heads and diameters and are used for cabinet making and attaching plywood paneling.
• Finishing nails: Fine woodwork and crafts or areas where nail heads are concealed are great places to use finishing nails.

Specialty nails: Not a hard and fast rule, but applications like drywall, roofing, framing, flooring, masonry, and duplex (double-headed nails used for temporary structures like scaffolding &#; not nails limited to duplex house construction) all have their own type of nail category. You can start your project in that category, or explore how other nails might also do the job for you.

Nail gun nails: These nails range in similar materials, gauges, and lengths to single nails, but you still need to be selective. Nail gun nails need to be strung or collated together so that they can be fed into a nail gun automatically. Nail guns are often used in repetitive projects that don&#;t necessarily require a lot of precision when it comes to the location of the nail, like when installing large pieces of asphalt shingles on a roof. Check your nail gun&#;s requirements regarding size and gauge of the nail that will fit, as well as the material they are collated with. Some guns may take glue, plastic, or paper-collated nails, but not wire-collated ones.

Different Nail Materials, Lengths, and Gauges (and Why They Matter)

Another aspect you&#;ll need to consider is the nail material. Common &#;bright&#; finish nails aren&#;t appropriate for every project. Bright nails are used mostly for indoor projects because they have no treatment that inhibits rust. Even indoors, some types of wood (redwood and cedar, for example) can react with bright nails. Use stainless steel, hot-tipped galvanized, or aluminum nails in these cases. Nails also come with a black-phosphate finish (used frequently on drywall nails to prevent corrosion and adhere well to paint and drywall mud) or zinc-plating (ideal for indoor projects where corrosion is a potential problem, as their thin coating inhibits rust), among other materials.

The length of your nails also makes a difference. As you&#;d expect, heavy-duty projects like framing or hanging drywall require a substantial, longer nail compared to a small project like installing thin molding or carpet. The smallest length of nail is often the 10 penny nail, which starts at a &#;2D&#; or &#;two penny&#; size, which is 1-inch long. They go up to a 60D length which is 6-inches long. There are different rules of thumb, but generally speaking a nail should be two to three times as long as the material you are hammering it into.

Fun fact: The term "penny nail" comes from 15th-centruy England and described the number of pence (pennies) needed to purchase 100 nails. The longer the nail, the higher the price.

In addition, the gauge, or diameter of your nail shank will also be influenced by your project. The smaller the gauge number, the wider the diameter of the nail. Note that even short-shank penny nails can come in large gauges.

From Big to Small, McCoy&#;s Has the Nails You Need

Questions? Ask one of the experts at McCoy&#;s about what nail lengths are right for your project! The experts at McCoy&#;s can help you make sense of any materials you need for your next project, from ten-penny to roofing nails. If you want to tackle building a shed or just repair a corner of an old deck, we can help you hit the right nail squarely on the head, every time.

The company is the world’s best type of nails construction supplier. We are your one-stop shop for all needs. Our staff are highly-specialized and will help you find the product you need.