The front and rear plates are made from 8 gauge (1/8") steel. The rivet holes are 1/8" and the keyhole is 9/32" diameter.
The spacer is made from 14 gauge steel 7/16" wide. The lugs are 1/4" diameter, 7/16" long with an 1/8" hole.
It's easiest to drill the holes in the lugs with a lathe, then grind and file the sides flat.
Clamp them in place and weld them with a small torch either on the ends or the sides.
The shackle is made from 5/16" diameter steel bent around a 13/16" diameter rod.
Clamp a piece of angle iron in a vice and clamp the 5/16" rod under the 13/16" and pull up on the 5/16".
The flat end can be made from a 3/8" x 7/16" x 7/16" steel block with a 5/16" hole for the shackle end.
It can also be made by building up with welds and then ground or filed flat.
The slider and block are made from 3/8" thick steel.
The white area shows where an 1/8" hole is drilled for the ball and spring.
Use a small bur to grind the two detents for the ball to snap into at the locked and unlocked positions.
The spring and ball are 1/8" diameter and can be bought at a hardware store.
The ball can also be found under the rear sprockets of mountain bikes.
After the ball and spring are installed, pein or center punch the edge of the hole to retain them.
The screws that hold the slider block are 5-40 threads.
Apply a small amount of grease at final assembly.
A keyhole cover can be added. Pein the pin so the cover flips out of the way.
The crimping dies are made from 5/8" steel with small round indentations in two ends to form the rivet heads.
Keyshafts are made from 3/16" with an 1/8" hole in one end.
The handles are made from 1/8" wire wrapped around a 7/16" rod.
They are welded, annealed, then squeezed in a vice to make them oval.
If they aren't annealed, they will form into a D shape.
After a groove is ground into the key shaft, the key blade can be wired in place for welding.
Why would I make a padlock when I can just buy one? Because I like cutting, bending, grinding, filing, drilling, peining, welding, hammering, measuring, sanding, polishing, annealing, hardening, tempering, turning and milling steel!
Any questions? Any comments? Did you make a padlock or something cool? Let me know.