Introduction: Welded Sai - Martial Arts Weapon (not for Cosplay)

About: Mad scientist, graphic designer, mechanical drafter, sci-fi geek.

Sai are a martial arts weapon most commonly associated with Okinawan Karate. They are also the signature weapon of Raphael from the Teenage Mutant Ninja Turtles.

This Instructable is about making a real pair of sai (NOT FOR COSPLAY) by cutting and welding steel bars.

For a great video about sai and the origin of karate check out this youtube video by the Karate Nerd Jesse EnKamp.

Supplies

1/2" diameter steel bars. Length will be determined by the size of sai you want to make. See step 2

1" diameter steels balls (2) for handle base.

Something to cut the steel. I used a combination of a Dremel cut-off wheel and a chop saw with an abrasive cutter

Mig Welder

Angle grinder and grinding disc

spray paint for metal

paracord to wrap the handle.

Step 1: Measure and Cut Steel Bars

Measure sai dimensions and cut steel bars to match.

Sai come in different sizes and the size you use depends on the length of your arm. Holding a ruler or the steel bar in one hand with your index finger extended. Measure from the tip of your index finger to a 1 to 3 inches past your elbow. This the length of the main bar. Also make note of where the connection of your thumb and index finger is on the bar. This will be where you will weld the guard onto the main bar.

See the attached drawing of the dimensions for the guard pieces. If you want to go the extra step you could cut the pieces out of wood dowel first to mock the design up in wood before cutting your metal pieces.

Step 2: Weld

Now it's time to weld the segments together. Layout the segments on the welding table and use the MIG welder to weld them together. This in not welding Instructable and I'm not a good enough welder to write one. The important thing is to get a strong weld and join the pieces together deeply. The guard is designed to catch and block weapons so it needs to be strong.

Step 3: Grind Welds

Now it's time to clean up the welds.

Using the angle grinder, grind down any excess material on the welds and joints. You can also do some shaping at this point. Traditional sai have rounded corners and the tip of the shaft and guard are rounded. The sai was a law enforcement tool designed to disarm and catch opponents not kill them.

Step 4: Paint

To keep the steel from rusting you will need to paint it. I used a black primer and then a silver cover.

Step 5: Wrap the Handle

To finish off the sai, wrap the handle in paracord. There are plenty of insturctables and youtube videos on how to do a paracord wrap.

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