Nail Geek — Frequently Asked Questions
When referring to nails what is a “penny” or “penny weight”?
What does the “d” mean on nails?
Does the “penny weight” or “d” tell me the length?
The penny weight of a nail refers to the price for a hundred nails in 15th century England. The larger the nail, the more "pennies" required to purchase 100 of them. Today, the penny weight is commonly, and many times, incorrectly used to refer to the length of a nail. The symbol for penny weight is "d", from the Latin word "denarius", roughly translated as coin (penny). A 2d (penny) common nail is 1" long. Each 1d (penny) is assumed to be an increase of 1/4" of length up to a 16d (3 1/2"). After 16d, nails jump to 20d (4") and increase in length by 1/2" by multiples of 10 (20d, 30d, 40d etc.) Nails longer than 6", are correctly referred to as "spikes" and identified simply by their length. The penny weight/length is not the same for ALL nails (eg. bulk “sinker” nails and many gun nails) and they not uniformly employed by all manufacturers. To avoid confusion it is best to call for a nail by the length and diameter.
What is a common nail?
What is a box nail?
What is a cooler nail?
What is a sinker nail?
What is the difference between a common, box, cooler and sinker nail?
“Common” nails have larger diameter shanks than box, cooler or sinker nails of the same “penny weight”. The heavy shank allows them to carry higher structural loads. “Box” nails have lighter (smaller diameter) shanks. They were originally designed to reduce splitting when used to assemble wooden “boxes”. The lighter shanks also meant that you received more nails (count) in a 50lb keg or carton. Similarly, cooler nails were designed to be installed by automatic equipment in wood and had a coating that made them easier to drive (vs. box nails). The coating (vinyl) “melts” when it was driven into the wood (friction) lubricating the nails for installation by pneumatic equipment (air nailers) and the coating bonds the nail to the wood when it “cools”: “Cooler”. The light shanks and coating on cooler nails made underpowered equipment more effective and, like the box nail, reduced splitting. Sinkers are also commonly vinyl coated. They get their name from the flat countersunk head that makes them easy to drive flush and beyond flush: counter-“sinking” them into the wood. The shanks are lighter than “common” nails but heavier than “box” or “coolers” and they are slightly shorter, by penny weight than a common nail. The idea being, you could easily drive them deeper than other nails and that the shank would thus penetrate further than if using a flat head nail, like a common, box or cooler nail. Most sinkers (bulk) also have a checked head making them easy to drive with a mill faced hammer at odd angles. The coating is intended to function in the same way that the coating works on a cooler nail. The heavier shanks make them a better choice for use in wood structures.
How do I select the correct nail length?
What is “toe nailing”?
For non structural applications, those without a engineered design, the rule of thumb is to use a fastener that is two (2) to three (3) times the length of the thickness of attaching member. For example: if attaching a 1” fascia board directly to wood framing a two (2”) to three (3”) inch nail would be a good choice. If applied over sheathing or other sub strait, add the sheathing/sub strait dimension to the total length of the fastener of choice. For additional withdrawal use a longer or thicker nail or use a nail with a deformed shank (ring or screw) or a performance finish (eg. phosphate coated).
ALWAYS avoid attaching a heavy material to a lighter material. Rather than attaching through a 1 ½” board to a ¾” board, drive the fastener through the ¾” into the 1 ½” material.
Toe nailing can provide greater strength than an attachment to end grain of a receiving member. A proper toe nail is driven at 30 degrees to the grains of the wood and into the attaching or main member at a point equal to 1/3 of the nail length.
If my prints call out a common nail, can I substitute a box, cooler or sinker nails?
First, no substitution should be made without prior approval from the engineer of record. That said, an engineer may be willing to allow a substitution for a lighter shank nail in favor of additional nails per connection or a tighter pattern. Some misinterpret language like “box nails may be substituted unless otherwise specified”. This reference does not allow for the use of shanks that are lighter than that specified. The language was added as pneumatic nail guns gained popularity. Early nail guns were only capable of “shooting” nails with lighter shanks. Today more efficient and powerful nailers are, for the most part, capable of driving nails with “common” shank diameters. The shank diameter or equivalent, as specified by the “penny weight” for a common nail, is still required unless proper approval for a substitution has been granted.
How does a ring or screw nail work?
Which is better? A ring or a screw nail?
What is a spiral or “ardox” nail?
A screw nail has a “screw like” thread rolled into the shank. In fact, It looks much like a wood screw. The nail rotates as it is driven into the wood. As it spins into the wood, it twists the wood fibers increasing resistance to withdrawal (pull out).
A screw nail is best for hard wood and if a threaded nail with a hot galvanized finish is required, the screw nail is commonly preferred. The screw nail resists withdrawal all of the way out, when being pulled. This is why screw nails are preferred for wood shipping “pallets” and are common on wood construction projects and applications where material is expected to “rack” or shrink.
A ring shank nail incorporates annular rings that force the wood fibers into the direction of the point before locking them into the rings. Ring shank nails provide excellent resistance in soft wood but may be hard to drive in harder wood species. A hot galvanized coating will flow into the rings and may reduce the holding power of a ring shank nail. Ring shank nails have very high initial withdrawal resistance, but once the wood fibers release the nail is easily removed. This is why they are used in many crating applications as well as wood framing and sheathing.
Most building codes recognize both ring shank and screw shank equally and accept either interchangeably as “threaded” nails.
Spiral or ardox nails are made from wire that has 4, 5 or 6 flat surfaces (rather than round wire). Before the head and point are forged the wire is twisted or spun. As they are made from “squared” wire, the heads are often not perfectly round. The final nail includes threads that runs all the way from the point to just below the head. Spiral nails are easier to drive than a screw or ring shank nail and increase holding power in much the same way that a screw nail functions. While proven to increase resistance to withdrawal, spiral nails are not currently recognized by most engineers as a substitute for a screw or ring shank nail. Spiral nails are especially preferred in longer lengths and diameters. They are most often the right choice for attaching large dimension lumber, landscape timbers and fences rails and boards. Spiral nails are especially effective when hot galvanized applications as the thread confirmation does not fill with zinc in the same way that a ring or screw nail will. Spiral nails are widely used when material is expected to “rack or shrink.
How can I reduce splitting?
Is this different on hardwood and softwood?
Splitting can be caused by many conditions. First, buy a good quality nail. A nail that bends, or threatens to bend will often increase splitting. Good points with equal tapers will drive straight and true. When possible, stay away from the edge of the material for nail placement. Drive the nail as straight as possible (perpendicular to the grain of the wood and drive the nail short of flush before countersinking it with a nail set. If this is not possible or if you still have splitting you can try “blunting” the nail point. By striking the point with a hammer, the point can be blunted. A blunted nail will tear wood fibers rather than separate or split them. You may also find that a smaller or lighter shank nail will reduce splitting. Try a “box” nail rather than a “common” nail or a finish nail rather than a casing nail. In structural connections these substitutions must be pre approved, but for the home project or non structural connection a lighter shank nail is often the best solution for splitting. Another solution is to pre-drill a hole just slightly smaller than the shank of the nail through the attaching member.
Nails in hardwood and softwood:
Because wood fibers hold a nail in place, nails driven into hardwood tend to resist pull out (withdrawal) better than those driven into softwood. Long sharp diamond points reduce damage to wood fibers when being driven, but tend to split hardwoods. A sharp diamond point aids withdrawal in properly dried softwoods.
Why are there different points on nails?
The nail point (diamond point) is a four sided taper. A very important eliment of quality is that the four tapers are equal and “clean”. This keeps the nail driving straight. Diamond and long diamond nails can be “stabbed” into the wood or gypsum to get them started leaving the “off hand” available to steady the material. This is a great feature when nailing into an awkward spot or when speed is important.
What is a Bright or Brite nail?
What is the meaning of "exterior" in reference to nails?
Bright (or brite) refers to “bright basic”. Bright nails are not coated with a protective finish and are not recommended for exterior exposure or use in treated lumber (ACQ). “Exterior exposure” assumes that the fasteners will have no water proof covering/barrier protection upon completion of the structure. Paint does not apply in this case. Bright nails are used in framing and sheathing applications as well as for metal connectors (hardware) when they will not receive extended or permanent exposure to weather, water or corrosives, so long as the nail does not come into contact with treated lumber (ACQ). While sheathing can be attached to untreated wood framing with bright nails, panelized exterior siding such as T111, which will not receive protection from a waterproof barrier, should only be installed with a nail that includes corrosion protection (hot dip galvanized or stainless as required by code). Users may elect to use a galvanized fastener in some coastal zones and when extended exposure is anticipated to inhibit rust, but this is mostly a decision based on aesthetics. It is always recommended that the local code requirements are fully investigated as some local codes may require corrosion protection for all fasteners.
What is “vinyl” coated?
How does it work?
Nails are commonly coated with vinyl to make them easy to drive. When a nail is driven into wood the surface temperature of the nail is increased by the friction. This friction is just enough to melt the coating and lubricate the nail. When the nail stops moving the vinyl cools and improves the withdrawal resistance. To work correctly, the nail must be thoroughly cleaned before the vinyl is applied. Many import nails are coated with what looks like vinyl, but the coating is not a true vinyl and does not function as one. It is simply a decorative coating to conceal the corrosion on the nail when shipping to the US. Most of the time, these coatings have a negligible positive effect for ease of drive or improved withdrawal.
What is “phosphate coated?
Nails are commonly coated with phosphate to increase the holding power. This coating also provides some modest resistance to corrosion. The chemical etching referred to as phosphate coating provides a good adhesive base to adhere drywall mud or paint. Manufacturers must closely monitor production when producing “phos” coated nails to ensure that they are not softened, and nails drive straight and true without bending
How does “Hot Dip” protect steel nails from corrosion?
If unprotected, steel will corrode in nearly any environment. Hot Dipping protects against corrosion by providing two types of protections
1) A physical barrier
2) Cathodic action
Physical barrier:
The Hot Dip coating provides a continuous, impervious barrier that prevents moisture from coming into contact with the steel. Unless the steel comes into contact with moisture or dissimilar metals, there is no reason to expect corrosion. Zinc will gradually erode, but has a much longer life than uncoated steel when exposed. Zinc is a highly durable physical barrier and is especially suited for nails that will be struck with a hammer or the driver of a nail gun for installation.
Cathodic Protection:.
Zinc deposited during the hot dip process galvanically protects the steel from corrosion (red rust). Should bare steel be exposed to moisture or other corrosives, the steel is protected by the sacrificial loss of zinc (white rust) in the vicinity of exposed steel. In the immediate presence of zinc, steel will not corrode until all the zinc has been sacrificed. Thus it is safe to say that the weight of zinc coating has a direct relationship to the useful life of a fastener in a specific environment.
When a fastener corrodes it loses load carrying capacity. A heavy coat of zinc extends the life of your project.
Why should I use a hot galvanized nail in treated lumber and ACQ?
ACQ replaced CCA treated lumber. CCA was an Arsenic based wood preservative. ACQ (Alkaline Copper Quaternary) replaced CCA to remove health risks associated with Arsenic. ACQ is highly corrosive due to high levels of copper. The transition to ACQ caused major problems at first. Even though suppliers of treated wood had long recommended hot dip galvanized fasteners, the recommendations had been mostly ignored. The industry took notice when exterior decks and railings started coming apart. Many homeowners were hospitalized with serious injuries when their second story decks and or railings collapsed. http://www.deckfailure.com/Failures.html.
Minor injuries were also reported when first story decks and railings failed. Property damage reports from failed pole buildings have also been recorded. The International Building Code and the International Residential Code both require all connections to and through treated wood (other than Borate) to be fastened with ASTM-A-153 Class D Hot Dip Galvanized or stainless steel fasteners.
Certain preservative treatments for wood may be highly corrosive. Consult the manufacturer/supplier for pertinent information and their fastener recommendation.
Are there times when a hot dip galvanized nail should not be used?
Hot dip galvanized nails may not be the best choice for use with cedar, redwood or cypress. Extracts that occur naturally in these wood species can cause black streaking as the oils react with the zinc and steel. Wet wood aggravates this condition.
No steel nail, with or without zinc coating, should be used where it could come into contact with stainless steel or other dissimilar metals.
What is Electro Galvanized?
Electro galvanized (clear zinc – silver, yellow incandescent galvanized YIG) nails are better described as electro plated. The coating of zinc is very thin and provides minimal resistance to rust. The finish is primarily a barrier coat and quite fragile. They are bright and shiny but should not be used where they will be exposed to corrosive elements or come in contact with treated lumber.
What is Mechanical Galvanized?
Zinc dust is cold tumbled with the nails to achieve a zinc coating. Mechanically galvanized nails might look like hot dip galvanized nails but the coating is fragile and there are frequently holes in the coating that allow moisture and corrosives to come in contact with the raw steel. This brittle coating is also prone to flaking and not a good substitute for hot galvanized nails.
What is a barrier coating /ceramic coating/ zinc aluminum polymer coating?
What is “Exterior galvanized”?
To date, all of the proprietary coatings that we have observed or inspected have been found to be zinc rich paints (coatings). These coatings are either organic or inorganic. When the finish is heated or “kilned” they are often called “ceramic”. To function as promised the zinc dust must be concentrated enough to provide for electrical continuity in the dried coating. If not, cathodic protection will not occur. Even in high concentrations, there are questions as to whether cathodic protection is possible at all due to the encapsulation of the zinc particles in the binder of the coating. Without cathodic protection, the coating performs little better than basic paint and can easily be damaged when installing the fastener. Some of these coatings make elaborate claims pointing to salt spray tests and offering extended warranties. Buyer beware. One such warranty was made invalid if installed in wet wood. Based on our own tests and observations a majority of barrier coatings are compromised when the nail is installed.
When should I use stainless steel nails?
Stainless steel nails are recommended for structural connections that are going to be continuously exposed to ocean salt air, de-icing salts and chemicals, fire retardants, fertilizers, soil, acid rain and other highly corrosive environments.
Stainless steel nails should be used anytime the fastener will come in contact with other stainless steel products (structural metal connectors etc)
Certain preservative treatments for wood may be highly corrosive. Consult the manufacturer/supplier for pertinent information and their fastener recommendation.
What is the difference between 304 and 316 stainless steel?
304 and 316 stainless steel are two of the most common grades of stainless steel. Both 304 and 316 grades are non magnetic. Stainless steel (304 and 316) are a combination of steel, chromium, nickel, and in the case of type 316, molybdenum. Grade 316 stainless is a better choice for coastal/marine exposure than 304.
What is ICC?
Is ICC the same as ICBO?
What does an ICC ESR report tell me?
ICC-ES is the International Code Council Evaluation Service. The ICC-ES performs tests to confirm the code compliance of building products (to the properties established by ASTM and NDS). Builders, contractors and specifiers have confidence in products that have current and valid ICC-ES reports.
You can confirm the validity of an ICC-ES ESR report on line at
http://www.icc-es.org/reports/index.cfm?search=search
ICC was founded by ICBO (International Council of Building officials), BOCA, and the SBCCI. The original mission of ICBO is being carried out today by the ICC Evaluation Service. Many ICBO report holders have been granted legacy reports allowing them time to secure ICC reports.
What is NDS?
The National Design Specification for Wood Construction provides structural values for common and specific wood assemblies. The NDS uses the specific gravities of different sawn wood species, sheathing and physical properties of fasteners (that meet the minimum requirements of ASTM) to determine these structural values.
What is ASTM?
The American Standard for Testing Materials (ASTM) publishes the minimum standards for many products. Nails and other fasteners are among the standards published. These standards include the dimensions of nails as well as the bend yields.
What is bend yield? Why is it important?
Bend yield is an important measure of the effectiveness of a nail. The shear value of a connection is a function of the nail withdrawal and bending resistance. When a fastener fails it first bends and then withdraws. The movement in a connection needs only move 3/8 of an inch to be deemed “failed”. This failure allows penetration of the structure by moisture and or pests.
What does the “d” mean on nails?
Does the “penny weight” or “d” tell me the length?
The penny weight of a nail refers to the price for a hundred nails in 15th century England. The larger the nail, the more "pennies" required to purchase 100 of them. Today, the penny weight is commonly, and many times, incorrectly used to refer to the length of a nail. The symbol for penny weight is "d", from the Latin word "denarius", roughly translated as coin (penny). A 2d (penny) common nail is 1" long. Each 1d (penny) is assumed to be an increase of 1/4" of length up to a 16d (3 1/2"). After 16d, nails jump to 20d (4") and increase in length by 1/2" by multiples of 10 (20d, 30d, 40d etc.) Nails longer than 6", are correctly referred to as "spikes" and identified simply by their length. The penny weight/length is not the same for ALL nails (eg. bulk “sinker” nails and many gun nails) and they not uniformly employed by all manufacturers. To avoid confusion it is best to call for a nail by the length and diameter.
What is a common nail?
What is a box nail?
What is a cooler nail?
What is a sinker nail?
What is the difference between a common, box, cooler and sinker nail?
“Common” nails have larger diameter shanks than box, cooler or sinker nails of the same “penny weight”. The heavy shank allows them to carry higher structural loads. “Box” nails have lighter (smaller diameter) shanks. They were originally designed to reduce splitting when used to assemble wooden “boxes”. The lighter shanks also meant that you received more nails (count) in a 50lb keg or carton. Similarly, cooler nails were designed to be installed by automatic equipment in wood and had a coating that made them easier to drive (vs. box nails). The coating (vinyl) “melts” when it was driven into the wood (friction) lubricating the nails for installation by pneumatic equipment (air nailers) and the coating bonds the nail to the wood when it “cools”: “Cooler”. The light shanks and coating on cooler nails made underpowered equipment more effective and, like the box nail, reduced splitting. Sinkers are also commonly vinyl coated. They get their name from the flat countersunk head that makes them easy to drive flush and beyond flush: counter-“sinking” them into the wood. The shanks are lighter than “common” nails but heavier than “box” or “coolers” and they are slightly shorter, by penny weight than a common nail. The idea being, you could easily drive them deeper than other nails and that the shank would thus penetrate further than if using a flat head nail, like a common, box or cooler nail. Most sinkers (bulk) also have a checked head making them easy to drive with a mill faced hammer at odd angles. The coating is intended to function in the same way that the coating works on a cooler nail. The heavier shanks make them a better choice for use in wood structures.
How do I select the correct nail length?
What is “toe nailing”?
For non structural applications, those without a engineered design, the rule of thumb is to use a fastener that is two (2) to three (3) times the length of the thickness of attaching member. For example: if attaching a 1” fascia board directly to wood framing a two (2”) to three (3”) inch nail would be a good choice. If applied over sheathing or other sub strait, add the sheathing/sub strait dimension to the total length of the fastener of choice. For additional withdrawal use a longer or thicker nail or use a nail with a deformed shank (ring or screw) or a performance finish (eg. phosphate coated).
ALWAYS avoid attaching a heavy material to a lighter material. Rather than attaching through a 1 ½” board to a ¾” board, drive the fastener through the ¾” into the 1 ½” material.
Toe nailing can provide greater strength than an attachment to end grain of a receiving member. A proper toe nail is driven at 30 degrees to the grains of the wood and into the attaching or main member at a point equal to 1/3 of the nail length.
If my prints call out a common nail, can I substitute a box, cooler or sinker nails?
First, no substitution should be made without prior approval from the engineer of record. That said, an engineer may be willing to allow a substitution for a lighter shank nail in favor of additional nails per connection or a tighter pattern. Some misinterpret language like “box nails may be substituted unless otherwise specified”. This reference does not allow for the use of shanks that are lighter than that specified. The language was added as pneumatic nail guns gained popularity. Early nail guns were only capable of “shooting” nails with lighter shanks. Today more efficient and powerful nailers are, for the most part, capable of driving nails with “common” shank diameters. The shank diameter or equivalent, as specified by the “penny weight” for a common nail, is still required unless proper approval for a substitution has been granted.
How does a ring or screw nail work?
Which is better? A ring or a screw nail?
What is a spiral or “ardox” nail?
A screw nail has a “screw like” thread rolled into the shank. In fact, It looks much like a wood screw. The nail rotates as it is driven into the wood. As it spins into the wood, it twists the wood fibers increasing resistance to withdrawal (pull out).
A screw nail is best for hard wood and if a threaded nail with a hot galvanized finish is required, the screw nail is commonly preferred. The screw nail resists withdrawal all of the way out, when being pulled. This is why screw nails are preferred for wood shipping “pallets” and are common on wood construction projects and applications where material is expected to “rack” or shrink.
A ring shank nail incorporates annular rings that force the wood fibers into the direction of the point before locking them into the rings. Ring shank nails provide excellent resistance in soft wood but may be hard to drive in harder wood species. A hot galvanized coating will flow into the rings and may reduce the holding power of a ring shank nail. Ring shank nails have very high initial withdrawal resistance, but once the wood fibers release the nail is easily removed. This is why they are used in many crating applications as well as wood framing and sheathing.
Most building codes recognize both ring shank and screw shank equally and accept either interchangeably as “threaded” nails.
Spiral or ardox nails are made from wire that has 4, 5 or 6 flat surfaces (rather than round wire). Before the head and point are forged the wire is twisted or spun. As they are made from “squared” wire, the heads are often not perfectly round. The final nail includes threads that runs all the way from the point to just below the head. Spiral nails are easier to drive than a screw or ring shank nail and increase holding power in much the same way that a screw nail functions. While proven to increase resistance to withdrawal, spiral nails are not currently recognized by most engineers as a substitute for a screw or ring shank nail. Spiral nails are especially preferred in longer lengths and diameters. They are most often the right choice for attaching large dimension lumber, landscape timbers and fences rails and boards. Spiral nails are especially effective when hot galvanized applications as the thread confirmation does not fill with zinc in the same way that a ring or screw nail will. Spiral nails are widely used when material is expected to “rack or shrink.
How can I reduce splitting?
Is this different on hardwood and softwood?
Splitting can be caused by many conditions. First, buy a good quality nail. A nail that bends, or threatens to bend will often increase splitting. Good points with equal tapers will drive straight and true. When possible, stay away from the edge of the material for nail placement. Drive the nail as straight as possible (perpendicular to the grain of the wood and drive the nail short of flush before countersinking it with a nail set. If this is not possible or if you still have splitting you can try “blunting” the nail point. By striking the point with a hammer, the point can be blunted. A blunted nail will tear wood fibers rather than separate or split them. You may also find that a smaller or lighter shank nail will reduce splitting. Try a “box” nail rather than a “common” nail or a finish nail rather than a casing nail. In structural connections these substitutions must be pre approved, but for the home project or non structural connection a lighter shank nail is often the best solution for splitting. Another solution is to pre-drill a hole just slightly smaller than the shank of the nail through the attaching member.
Nails in hardwood and softwood:
Because wood fibers hold a nail in place, nails driven into hardwood tend to resist pull out (withdrawal) better than those driven into softwood. Long sharp diamond points reduce damage to wood fibers when being driven, but tend to split hardwoods. A sharp diamond point aids withdrawal in properly dried softwoods.
Why are there different points on nails?
The nail point (diamond point) is a four sided taper. A very important eliment of quality is that the four tapers are equal and “clean”. This keeps the nail driving straight. Diamond and long diamond nails can be “stabbed” into the wood or gypsum to get them started leaving the “off hand” available to steady the material. This is a great feature when nailing into an awkward spot or when speed is important.
What is a Bright or Brite nail?
What is the meaning of "exterior" in reference to nails?
Bright (or brite) refers to “bright basic”. Bright nails are not coated with a protective finish and are not recommended for exterior exposure or use in treated lumber (ACQ). “Exterior exposure” assumes that the fasteners will have no water proof covering/barrier protection upon completion of the structure. Paint does not apply in this case. Bright nails are used in framing and sheathing applications as well as for metal connectors (hardware) when they will not receive extended or permanent exposure to weather, water or corrosives, so long as the nail does not come into contact with treated lumber (ACQ). While sheathing can be attached to untreated wood framing with bright nails, panelized exterior siding such as T111, which will not receive protection from a waterproof barrier, should only be installed with a nail that includes corrosion protection (hot dip galvanized or stainless as required by code). Users may elect to use a galvanized fastener in some coastal zones and when extended exposure is anticipated to inhibit rust, but this is mostly a decision based on aesthetics. It is always recommended that the local code requirements are fully investigated as some local codes may require corrosion protection for all fasteners.
What is “vinyl” coated?
How does it work?
Nails are commonly coated with vinyl to make them easy to drive. When a nail is driven into wood the surface temperature of the nail is increased by the friction. This friction is just enough to melt the coating and lubricate the nail. When the nail stops moving the vinyl cools and improves the withdrawal resistance. To work correctly, the nail must be thoroughly cleaned before the vinyl is applied. Many import nails are coated with what looks like vinyl, but the coating is not a true vinyl and does not function as one. It is simply a decorative coating to conceal the corrosion on the nail when shipping to the US. Most of the time, these coatings have a negligible positive effect for ease of drive or improved withdrawal.
What is “phosphate coated?
Nails are commonly coated with phosphate to increase the holding power. This coating also provides some modest resistance to corrosion. The chemical etching referred to as phosphate coating provides a good adhesive base to adhere drywall mud or paint. Manufacturers must closely monitor production when producing “phos” coated nails to ensure that they are not softened, and nails drive straight and true without bending
How does “Hot Dip” protect steel nails from corrosion?
If unprotected, steel will corrode in nearly any environment. Hot Dipping protects against corrosion by providing two types of protections
1) A physical barrier
2) Cathodic action
Physical barrier:
The Hot Dip coating provides a continuous, impervious barrier that prevents moisture from coming into contact with the steel. Unless the steel comes into contact with moisture or dissimilar metals, there is no reason to expect corrosion. Zinc will gradually erode, but has a much longer life than uncoated steel when exposed. Zinc is a highly durable physical barrier and is especially suited for nails that will be struck with a hammer or the driver of a nail gun for installation.
Cathodic Protection:.
Zinc deposited during the hot dip process galvanically protects the steel from corrosion (red rust). Should bare steel be exposed to moisture or other corrosives, the steel is protected by the sacrificial loss of zinc (white rust) in the vicinity of exposed steel. In the immediate presence of zinc, steel will not corrode until all the zinc has been sacrificed. Thus it is safe to say that the weight of zinc coating has a direct relationship to the useful life of a fastener in a specific environment.
When a fastener corrodes it loses load carrying capacity. A heavy coat of zinc extends the life of your project.
Why should I use a hot galvanized nail in treated lumber and ACQ?
ACQ replaced CCA treated lumber. CCA was an Arsenic based wood preservative. ACQ (Alkaline Copper Quaternary) replaced CCA to remove health risks associated with Arsenic. ACQ is highly corrosive due to high levels of copper. The transition to ACQ caused major problems at first. Even though suppliers of treated wood had long recommended hot dip galvanized fasteners, the recommendations had been mostly ignored. The industry took notice when exterior decks and railings started coming apart. Many homeowners were hospitalized with serious injuries when their second story decks and or railings collapsed. http://www.deckfailure.com/Failures.html.
Minor injuries were also reported when first story decks and railings failed. Property damage reports from failed pole buildings have also been recorded. The International Building Code and the International Residential Code both require all connections to and through treated wood (other than Borate) to be fastened with ASTM-A-153 Class D Hot Dip Galvanized or stainless steel fasteners.
Certain preservative treatments for wood may be highly corrosive. Consult the manufacturer/supplier for pertinent information and their fastener recommendation.
Are there times when a hot dip galvanized nail should not be used?
Hot dip galvanized nails may not be the best choice for use with cedar, redwood or cypress. Extracts that occur naturally in these wood species can cause black streaking as the oils react with the zinc and steel. Wet wood aggravates this condition.
No steel nail, with or without zinc coating, should be used where it could come into contact with stainless steel or other dissimilar metals.
What is Electro Galvanized?
Electro galvanized (clear zinc – silver, yellow incandescent galvanized YIG) nails are better described as electro plated. The coating of zinc is very thin and provides minimal resistance to rust. The finish is primarily a barrier coat and quite fragile. They are bright and shiny but should not be used where they will be exposed to corrosive elements or come in contact with treated lumber.
What is Mechanical Galvanized?
Zinc dust is cold tumbled with the nails to achieve a zinc coating. Mechanically galvanized nails might look like hot dip galvanized nails but the coating is fragile and there are frequently holes in the coating that allow moisture and corrosives to come in contact with the raw steel. This brittle coating is also prone to flaking and not a good substitute for hot galvanized nails.
What is a barrier coating /ceramic coating/ zinc aluminum polymer coating?
What is “Exterior galvanized”?
To date, all of the proprietary coatings that we have observed or inspected have been found to be zinc rich paints (coatings). These coatings are either organic or inorganic. When the finish is heated or “kilned” they are often called “ceramic”. To function as promised the zinc dust must be concentrated enough to provide for electrical continuity in the dried coating. If not, cathodic protection will not occur. Even in high concentrations, there are questions as to whether cathodic protection is possible at all due to the encapsulation of the zinc particles in the binder of the coating. Without cathodic protection, the coating performs little better than basic paint and can easily be damaged when installing the fastener. Some of these coatings make elaborate claims pointing to salt spray tests and offering extended warranties. Buyer beware. One such warranty was made invalid if installed in wet wood. Based on our own tests and observations a majority of barrier coatings are compromised when the nail is installed.
When should I use stainless steel nails?
Stainless steel nails are recommended for structural connections that are going to be continuously exposed to ocean salt air, de-icing salts and chemicals, fire retardants, fertilizers, soil, acid rain and other highly corrosive environments.
Stainless steel nails should be used anytime the fastener will come in contact with other stainless steel products (structural metal connectors etc)
Certain preservative treatments for wood may be highly corrosive. Consult the manufacturer/supplier for pertinent information and their fastener recommendation.
What is the difference between 304 and 316 stainless steel?
304 and 316 stainless steel are two of the most common grades of stainless steel. Both 304 and 316 grades are non magnetic. Stainless steel (304 and 316) are a combination of steel, chromium, nickel, and in the case of type 316, molybdenum. Grade 316 stainless is a better choice for coastal/marine exposure than 304.
What is ICC?
Is ICC the same as ICBO?
What does an ICC ESR report tell me?
ICC-ES is the International Code Council Evaluation Service. The ICC-ES performs tests to confirm the code compliance of building products (to the properties established by ASTM and NDS). Builders, contractors and specifiers have confidence in products that have current and valid ICC-ES reports.
You can confirm the validity of an ICC-ES ESR report on line at
http://www.icc-es.org/reports/index.cfm?search=search
ICC was founded by ICBO (International Council of Building officials), BOCA, and the SBCCI. The original mission of ICBO is being carried out today by the ICC Evaluation Service. Many ICBO report holders have been granted legacy reports allowing them time to secure ICC reports.
What is NDS?
The National Design Specification for Wood Construction provides structural values for common and specific wood assemblies. The NDS uses the specific gravities of different sawn wood species, sheathing and physical properties of fasteners (that meet the minimum requirements of ASTM) to determine these structural values.
What is ASTM?
The American Standard for Testing Materials (ASTM) publishes the minimum standards for many products. Nails and other fasteners are among the standards published. These standards include the dimensions of nails as well as the bend yields.
What is bend yield? Why is it important?
Bend yield is an important measure of the effectiveness of a nail. The shear value of a connection is a function of the nail withdrawal and bending resistance. When a fastener fails it first bends and then withdraws. The movement in a connection needs only move 3/8 of an inch to be deemed “failed”. This failure allows penetration of the structure by moisture and or pests.