3/8th Marlinspike




Introduction: 3/8th Marlinspike

About: Awesome Gear I've designed myself.

I made this marlinspike to make paracord knot work easier. The turkshead knot at the top acts as a knob which fits into your palm. I machined it from 3/8" aluminum bar. You can read more about marlinspikes below.

Marlinspike (/ˈmɑrlɨnspaɪk/; sometimes marlin spike, marlinespike, or the archaic marlingspike/marling-spike) is a tool used in marine ropework.

Shaped in the form of a polished metal cone tapered to a rounded or flattened point, they aid in such tasks as unlaying rope for splicing, untying knots, drawing marline tight using a marlinspike hitch, and as a toggle joining ropes under tension in a belaying pin splice.

Most marlinspikes are 6 to 12 inches long, but may reach 2 feet and more for working heavy cables and ropes. They are usually made from iron or steel, whereas fids, similar in shape and function, are formed from wood or bone. The marlinspike may be a separate tool or one item on a pocket knife.

Sailors who become proficient at knot tying, splicing, and sewing using the marlinspike are said to have mastered marlinespike seamanship, earning them the right to be known as marlin spikes or marlinspike seamen.

Source: Wikipedia

Step 1: Machine the Point

I offset my lathe carriage to 5 degrees. I then ran the cutting bit back and forth until a point formed. You don't want the tip too sharp otherwise it will pierce paracord rather than slip around it.  

Step 2: Smooth Out the Shoulder

To ease the shoulder left behind from the 5 degree cut, I ran a file over the spike. Doing this makes it much easier to push the spike all the way through a knot. I then used sand paper to remove the tooling marks. 

Step 3: Trim and Cut the Top

I didn't do an exact measurement. I just placed the spike in the palm of my hand and marked it so the length would be a couple guessed inches past my index finger. I then cut it down with a pipe cutter and machined the end round. 

Step 4: Cut the Turks Head Groove

Using my calipers I measured and marked 15mm.  I then cut a groove about 2mm deep. This will keep the turks head knot in place while the spike is in use. 

Step 5: Polish

I polished the spike with a buffing wheel and polishing compound. This step is important. You'd be surprised how much more difficult it is to push an unpolished spike through a knot. 

Step 6: Add the Knot

I followed this knot tying tutorial here. Using a paracord needle I ran a second pass and pulled it tight into the groove. I then trimmed the ends and tucked them in.

Thanks for reading.

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    7 years ago

    Made this out of half a knitting needle. thanks


    8 years ago on Introduction

    As nice done and traditional as that knot is for a Marlinspike you could also make a round knob out of some exotic wood. It would feel much better on the palms.

    Great tutorial. I just picked up an old lathe a few weeks ago and am antsy about doing a newbie project on it. Still learning how to make tooling for it (and failing).


    8 years ago on Introduction

    Great Instructable. Seeing that chuck sticking out of the three jaw reminded me of what a good job my machine shop instructor did in preventing students from developing that hazardous habit. The third time he caught a student leaving a key in the chuck, they were expelled on the spot and not allowed to continue the course. Only happed to one guy. The rest of us were made believers. :-)


    8 years ago

    Great tutorial. Great history. Minor omission, best used with a sailors palm.