Measure the diameter and the depth of the pin’s hole with the measuring tape. Get metal pins that are the proper diameter. The pins will probably be a little too long for the hole as they are.
Put on your goggles and gloves. Position the metal pin near the hacksaw at the proper length. Cut the pin to be the exact same length as the depth of the bunk bed holes.
Put the pin in a vise lengthwise and cut into the pin with the hacksaw. If you're using a stationary power hacksaw, turn on the power and slowly lower the blade onto the metal pin to cut it. If you're using a handheld power hacksaw, turn the power on and press the blade into the pin until it's cut through. If you're using a regular hacksaw you'll have to move the saw back and forth over the pin until you cut through the metal. Repeat this process on all the pins until you have enough for the bunk bed.
Slip the newly crafted pins into the holes once the bunk beds are stacked on top of each other.