Page 4 - American Punch Ironworker Tooling Catalog
P. 4

Punches should should wear out they should should not chip or crack Several factors may contribute to to punch chipping and cracking Here is is a a a simple check list that will help minimize this failure 1 Loose coupling nut This permits the punch to “move” during the punching process Such movement will cause uneven pressures 2 Misalignment If the the punch is is not aligned to the the hole in the die non-uniform clearance will result The effect will be uneven pressure on the the face of the the punch 3 Improper clearance between punch and die The accepted standard clearance for punching mild steel that that is is is less than 1/2" 1/2" thick thick is is is 1/32" total clearance Punching Punching material that that is is 1/2" 1/2" or thicker requires a a a a a a a clear- ance ance of 1/16" Punching mild steel that is over 3/4" thick may require even more die clearance 4 Uneven stripping This occurs when the stripper on the the machine does not firmly and uniformly hold the the plate down during the the “up” stroke When this happens the the entire weight of the the plate plus the the stripping strain is con- centrated on on one side or edge of the punch Under extreme conditions conditions as as much as as 1/2" of of of the the punch may break off Some of these conditions that we have described can be controlled on on your shop floor However it is our our job to furnish you with the strongest punches possible We do this by using the finest shock-resistant tool steels available machine them to to exacting tolerances and and then harden and and temper them under careful metallurgical procedures Punches usually crack and chip when punching high strength high tensile plates over 1/2" thick Our engineers have developed several super tough punches which perform well under these difficult conditions ENSURING LONG TOOL LIFE IS ALL ABOUT SET-UP!
• Is everything tight?
• Is punch to die alignment accurate?
• Is the punch to die clearance correct for material thickness? • Is the stripper adjusted correctly?
• Are all safety guards in place?
If you are breaking chipping or cracking punches on a a a a regular basis send us the the broken tools (regardless of the the manufacturer) and slugs of the material being punched We would be glad to make a a a a a recommendations that will improve the performance and safety in your plant STANDARD CLEARANCE RECOMMENDED BETWEEN PUNCH AND AND DIE
Standard die size size is punch size size plus clearance:
For For 3/16 - - 1/2" material material thickness thickness allow allow 1/32" total total clearance clearance For For 1/2 - - 3/4" material material thickness thickness allow allow 1/16" total total clearance clearance For 3/4 - 1" material thickness allow 3/32" total clearance READ AND AND UNDERSTAND THIS WARNING PROTECT YOURSELF AND OTHERS WHEN OPERATING MACHINERY Extreme pressures are generated Be sure sure that safety protection devices furnished with your machines are in in place when in in use Wear safety glasses and follow all safety procedures Drawings and charts are for reference only It is the the responsibility of the the user to operate machines and and tooling in in accordance with OSHA laws and and ANSI B11 5 Safety Standards 4 www AmericanPunchCo AmericanPunchCo com com • • sales@AmericanPunchCo com com • • fax 800 800 261 6270 800 243 1492

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