A horseshoe nail is the specialised fastener that secures a horseshoe to a horse’s hoof. It is not a generic nail — horseshoe nails are manufactured to very specific tolerances, with a geometry designed to pass cleanly through the hoof wall, emerge at the correct point on the outside of the hoof, and clench securely without splitting the horn or penetrating sensitive tissue. Getting the nailing right is one of the defining skills of a good farrier.
Design and Construction
A horseshoe nail has a distinctive shape quite unlike a carpentry nail. Key features include:
- A rectangular, tapered shank — the shaft of the nail is not round but rectangular in cross-section, with a bevel on one face toward the tip. This bevel causes the nail to curve slightly as it is driven, directing it away from the sensitive laminae and toward the outer hoof wall surface.
- A wide, flat head (the head) — the head of the nail is wide and angled to sit flush within the countersunk nail hole punched into the horseshoe. It bears the driving force and anchors the nail in the shoe once the clenching is complete.
- A distinct “inside” face — the smooth, non-bevelled face of the nail shank must always face inward (toward the frog) when driven. Driving a nail with the bevel facing inward rather than outward will direct the nail toward the sensitive laminae rather than away from it, risking a nail prick.
Horseshoe nails are almost exclusively made from steel, though nail composition, hardness, and manufacturing precision vary between brands and grades. Premium nails from manufacturers such as Mustad (a Norwegian company that has produced horseshoe nails since the 19th century) are used by professional farriers competing in championship shoeing competitions, where consistency and predictability are paramount.
Sizes and Selection
Nails are sized by a numbering system — typically E3, E4, E5, and upward, or equivalent designations depending on the manufacturer. Larger numbers indicate a heavier, larger nail suited to bigger shoes and heavier hoof walls. The correct nail size depends on the shoe being used and the thickness and condition of the horse’s hoof wall. Using too large a nail in a thin-walled hoof risks cracking the wall; too small a nail in a heavy shoe may not clench securely.
The Shoeing Process
Once the shoe is positioned on the trimmed and balanced foot, the farrier drives nails through the pre-punched nail holes in the shoe at a carefully controlled angle. The goal is for the nail tip to emerge through the outer hoof wall approximately one-third of the way up from the ground surface — close enough to the shoe to have a strong clench, but not so high as to weaken the wall. Typically six to eight nails are used per shoe, depending on shoe size and the horse’s workload.
After all nails are driven, the tips protruding from the wall are nipped short with nail cutters and then bent down tight against the hoof wall using a buffer and hammer — this is the “clench.” A well-formed clench lies flat and smooth, flush with the wall surface. The whole perimeter of the shoe is then finished with a rasp to produce a clean junction between hoof and shoe.
A nail prick — where a nail inadvertently penetrates the sensitive laminae — causes immediate lameness. The nail is immediately removed, the site disinfected, and the horse monitored closely. Deeper pricks can introduce infection and require veterinary attention. A close nail (one that passes very near but does not quite penetrate the sensitive tissue) may cause mild soreness that resolves over a few days.
Frequently Asked Questions
Why can’t you use ordinary nails to shoe a horse?
Because ordinary nails are not designed to work safely within the specific biomechanics of the hoof. The bevel and rectangular cross-section of a horseshoe nail are what cause it to curve outward through the hoof wall rather than driving straight through. Without this designed curve, a nail would be far more likely to drive into the sensitive inner hoof structures, causing injury. The head shape and nail hole design also work as a matched system — a generic nail simply would not sit correctly in the shoe or provide a reliable clench.
How many nails does a horseshoe need?
Typically six to eight nails per shoe, placed evenly along the toe and quarters of the shoe. The heel area of the shoe is generally left unnailed — nails placed too far back in the heel can restrict the natural expansion and contraction of the hoof with each footfall. The exact number depends on shoe size, the horse’s work level, and the farrier’s judgement. Racehorses with lightweight aluminium racing plates may use fewer nails due to the reduced weight and stress involved.
What happens to the old nails when a shoe is removed?
Before a shoe is pulled, the farrier uses a buffer and hammer to drive each clench up, releasing the tight fold of nail from the hoof wall. This prevents tearing the wall surface when the shoe is levered off. The old nails are driven out of the shoe and discarded — they are single-use items and should never be reused, as even minor metal fatigue or deformation from the first use makes them unreliable for subsequent shoeing.