Mittler Bros Machine & Tool 100-U - Manual (Page 4)

Punch To Die Rule Of Thumb
Aluminum = 10% Material Thickness
Mild Steel = 10% Material Thickness
Stainless Steel = 15% Material Thickness
WHEN NOTCHING 0.120” OR THICKER
WALL THICKNESS PIPE OR TUBING
Install Additional 0.005” Thick Brass Shim
plus the standard 0.015” shim between female die & notcher frame =
0.020” total shim thickness
See item 20 (Drwg. 100) or item 21 (Drwg. 100-U)
#100-104 0.005” Thick Brass Shim - Qty. 2