[Bob Bidonde]

0.25" thick cold rolled steel is more than adequate for an engine hoisting tool. What will determine the strength of your homemade tool is its design (shape and hole placements). Be conservative. Keep all holes 2 diameters away from any edge. Space holes no closer than 4 diameters. Keep hole diameters no larger than necessary. Make the vertical height of the tool 4 inches or more. Make the length to span all 4 spark plug holes. Avoid making any angle bends.