1x6-5/16” BS Screw Spike for Railroad Use

What the Designation 1x6-5/16" Means

The designation describes the two dimensions that matter for a screw spike: a 1-inch nominal shank diameter and a 6-5/16 inch overall length. The "BS" prefix refers to the British Standard family for railway track fastenings - the spike is manufactured to BS64 normal-strength requirements, which define the material, dimensions and mechanical properties for this class of fastener. It is one of the standard sizes used on timber and composite sleeper track and in turnout (switch) areas where strong, repeatable holding is required.

Material and Finish

The spike is manufactured from carbon steel and finished with a hot-dip galvanised coating. Hot-dip galvanising deposits a thick zinc layer that protects the steel in coastal, tunnel, high-humidity and ballast-contaminated environments, where ordinary oiled or painted fasteners would corrode quickly. The galvanised finish also gives a long, predictable service life with minimal maintenance, which is why it is the standard specification for outdoor track fasteners.

Mechanical Properties

For this class of BS screw spike, the mechanical specification is defined on the basis of tensile strength and toughness: a tensile strength in the range of 775–925 N/mm², an elongation around 20%, and an impact toughness (KCU) of at least 65 J. These values are what make the spike behave as a high-strength fastener rather than a general-purpose screw: it resists the repeated vertical and lateral forces of passing trains without loosening or fracturing, and the toughness requirement protects against brittle failure in cold weather.

Why a Screw Spike Instead of a Dog Spike

Compared with a plain dog spike, the screw spike has a threaded shank that bites into the sleeper over its full length. The practical consequences: pull-out resistance is roughly 0.5 to 1.0 times higher than a dog spike of comparable size, so the rail stays held under high uplift forces. The trade-off is real: lateral (thrust) resistance is lower - in the order of 50% less - and installation and removal are slower, which makes gauge adjustment more difficult. This is why screw spikes are preferred in turnouts and on lines with strong vertical forces, while dog spikes remain common on plain timber-sleeper track where speed of maintenance matters.

Typical Applications

Turnouts and crossings where holding force and reliability are critical.

Timber and composite sleeper track on main lines and secondary lines.

Bridges and approaches where uplift forces are high.

Industrial, port and mining railways with heavy axle loads.

Installation and Inspection Notes

Install with the correct pre-drilled pilot hole for the sleeper species - over-drilling loses grip, under-drilling splits the timber. Tighten to a consistent torque so that all spikes in a fastening share the load evenly. In service, check for corrosion at the sleeper surface line, for back-out (loosening), and for cracking of the timber around the hole. A galvanised spike that shows heavy zinc depletion or rusting at the thread should be replaced during the maintenance cycle.

FAQ

What is the difference between a screw spike and a dog spike?

A dog spike is driven, has a smooth shank and holds mainly by friction and bearing; a screw spike is threaded and screwed in, giving higher pull-out resistance but lower lateral resistance and slower installation.

Can the BS screw spike be used on concrete sleepers?

Not directly. Concrete sleepers use a different fastening concept - screw spikes that engage plastic dowels or cast-in sleeves, with lengths matched to the sleeper. The timber-track screw spike is specified for timber and composite sleepers.

Why is hot-dip galvanising preferred for track spikes?

Because track fasteners are exposed to water, ballast chemicals and salt for decades. Hot-dip galvanising gives a thick, durable zinc coating that protects the steel far longer than paint or oil, and it self-heals minor scratches by sacrificial action.

What does BS64 define for this spike?

BS64 is the British Standard for railway rails and associated track material; for this product it defines the normal-strength class, dimensional tolerances and the mechanical requirements (tensile strength, elongation and impact toughness) that the spike must meet.

How is the pull-out resistance tested?

By pulling a spike installed in a standard test block with a calibrated machine and recording the force at which it begins to move or withdraws. The test value is compared with the requirement to verify the spike and the installation practice.