The Meccano boss is an essential part for any Meccano model engineer.
Below are the four tools necessary to enable
standard Meccano type bosses to be fitted to any part in any position,
as carried out by me on Mecarep compatible parts.
Note: Bosses for narrow strips. The No 4 tool is slightly different as the shoulder on the boss is Ø1/4" and Ø A is 17/64" (0.265") as shown on my standard bossed narrow cranks. Micro bossed narrow cranks are Ø 5/16" x 3/16" long and have 8 B.A. Threads.
BOSSES - See box Right hand bottom above. The shoulder length B - 1/16" (0.062") as the Minimum. I use this measurement for most bossing operations on all standard gauge Meccano parts including narrow strips. The No 1series of strips are thicker gauge and need 2mm minimum (0.080") to be effective (I make mine 3/32" and for doubled up parts such as a fabricated bell crank I increase it to 3mm (0.120")
NOTE - In general engineering bench
fitting terms, the basic rule of thumb to establish the length for SOLID
riveting is - Total Thickness of material to be joined plus 1 extra gauge