Introduction: Skeleton Arm, Made by Penguin Manufacturing

Welded sculpture of a human arm.

Step 1: Tools

  • MIG welder with Argon/CO2 75/25
  • Plasma cutter,(Or anything to cut steel Plasma Cutter is preferred)
  • Bench grinder
  • Angle grinder
  • MIG pliers
  • Wire brush
  • Safety gear: Leather gloves, jacket, welding hood, safety goggles.

Step 2: Materials

From left to right...

  • 3/8 in. all thread bolt, 9 in. long (16 TPI) 1x
  • 3/8 in. all thread bolt, 8 1/2 in. long (16 TPI) 1x
  • 1/4 in. 3 in. long hex-bolt (20 TPI) 4x
  • 5/16 in. 2 in. long hex-bolt (24 TPI) 2x
  • 5/16 in. 1 1/2 in. long hex-bolt (24 TPI) 12x
  • 5/16 in. 1/2 in. long hex-bolt (24TPI) 1x
  • 5 in wide, 6 in long U-channel (5mm)
  • 1/2 in. nut 9x

Step 3: Make a Base

Cut U-channel into a roughly 5' by 6' block for the base of the structure.

Grind with angle grinder to get a smoother non-rusted surface.

Step 4: Make Ulna and Radius.

Grind 45 degree angles into both all thread bolts to make "ulna" and "radius" bones.

Step 5: Ready to Weld!

I found the optimum voltage for this project to be 20 volts.

Step 6: Tack, Tack, and More Tack.

Arrange the pieces as shown.

Tack weld the ulna and radius angle side down.

Weld the nuts on as wrist bones.

Tack weld the rest of the bones on piece by piece as shown until you have a skeleton arm!

Step 7: Cleaning

After welding it all together take your wire brush and brush off any residue, (from welding zinc).

Use an angle grinder to clean welds up, and you're done!