Unknown punch

[Copymutt]

While looking for DC power supplies today came across this Malco NHP1 punch. Anybody have an idea what it’s purpose is?

 

[paulsomlo]

It's for making slots for fasteners, in vinyl/aluminum siding, in order to accommodate thermal expansion/contraction. For places where you need to fasten, but there's no factory slot.

 

[KnurledNut]

NHP = nail hole punch

 

[Copymutt]

Thanks much. No longer a mystery.

 

[vpd66]

I've seen a punch like that used for screw holes in metal roofing. A slot is required to allow the metal to expand and contract has it heats and cools.