How to Forge a Railroad Spike

Although not ideal for creating a good quality knife, railroad spikes offer an opportunity for the rookie blacksmith to learn forging.

The forging of metal was one of mankind's first and greatest technological leaps. A hundred years ago, every town had a blacksmith, but demand and modern production methods have made what was once an essential skill into a rare art. In the last two decades, blacksmithing has experienced a resurrection of sorts, and the shaping of metal has become a fairly common hobby. If you have thought about taking up the "black art," you may want to consider making something new out of something found.

Things You'll Need

• Railroad spike
• Forge
• Blacksmith's tongs
• Chisel
• Hammers
• Wire brush
• Bucket of ash or vermiculite
• Bench grinder
• Sandpaper
• Sanding block
• Coarse sharpening stone
• Quenchant (oil is preferred)
• Dishwashing liquid
• Kitchen oven
• Steel wool, 0000

Instructions

Heating and Shaping the Spike

1. 

   A pair of tongs with the right jaws is essential for holding the metal correctly and ensuring both your safety and a solid grip for forging.

   Place the spike in the forge and bring it to forging temperature (2,300 to 2,400 degrees F) or "straw yellow" in color.

2. Remove the spike from the forge and place it on the anvil; lightly mark the front of the handle (about 5 inches from the head of the spike) with a chisel and hammer. This will be the point beyond which you will not apply the hammer and any shaping other than knocking down the corners of the shaft of the spike.

3. Return the spike to the forge and bring it back up to forging temperature.

4. 

   The horn of the anvil will provide a good back for drawing out the length of your spike.

   Place the spike on the horn of the anvil (or on some radiused surface -- like a section of railroad track) and draw out the length of the spike with your hammer from your chisel marks to the tip. When the spike cools to below forging temperature, return it to the forge.

5. Continue forging the blade end of the spike until it is thin enough (around 1/8th inch) along its entire length (it should also taper toward the tip). Check frequently for straightness and adjust if necessary.

6. Heat the blank to forging temperature again; then anneal it by placing it in a bucket of ash or vermiculite or leaving it in your forge (after it has been shut down) to cool very slowly.

7. Profile the blade; then grind your edges on the bench grinder. Sand the flats to remove ripples and grind marks.

8. 

   Use a coarse sharpening stone to bring out the edge.

   Grind the edge again with a coarse sharpening stone.

9. Re-start the forge and place your spike-knife in it; bring it up to forging temperature.

10. Remove the knife from the forge and quench it in the oil, stirring it as you do.

11. 

    Use a typical kitchen oven to temper your blade, but wash off the oil to avoid nasty fumes.

    Wash the knife with dish-washing liquid to remove any residue; then temper it through two 1-hour cycles at 450 to 500 degrees in your kitchen oven.

12. Polish with progressive-grit sandpaper and 0000 steel wool.

Tips & Warnings

• "Drawing out" the length of the blade is an art that can only be mastered through practice with the forge, hammer and anvil. Strike the metal more on the end away from the point, and then number your strikes progressively toward the tip as the metal thins.

• Wear the usual safety gear, especially eye protection, and a long-sleeve shirt.

• Use a wire brush to knock off the scale each time the blade comes out of the forge to minimize the chance of hot slag contacting and burning your skin and clothes.

• Some of these steps will require the assistance of a second person.

References

• Great Northern Railroad Spike Knives
• RR-Spikes: Spike Material and Use

Resources

• Bad Attitude Farm and Forge