Ironworker - V-block and blade

[dfkrug]

LOL yea right, it's 26 pages. Didn't I hear you say that once before?

I read most of it! I was pretty long, so if I missed some answer you already
gave, I hope you don't mind re-posting. The videos really show how
effective your design and fabrication was for the brake and the rake.

I got a HF air-over-hyd 20T jack, too, but I have not used it with my 20T
press. I think I should have gotten the 35T or 50T press, but the one I have
has worked well and I have used it tons. (Don't you hate it when you
should have bought bigger?)

These ironworkers come up on Craigs periodically and I lusted over them
for a while, but I decided that I do not want to dedicate the floor space and
pay the cost. I paid a guy with a real old 40T unit to punch a bunch of
holes in 1/2" plate for me. 1-1.5" holes are a real drag to drill. Now I have
the biggest drill press I could find and use plasma where I can.

 

[F.L. Jennings]

Those machines are very handy, I used to write programs for a Whitney 45ton plasma punch.

Keep in mind that there is a limit to what you can punch though (hole diameter vs. metal thickness combined with shear strength of the metal. You can bust or blow up the punch or die by coupling the wrong size punch with too thick/too high of a shear strength metal. Always check your chart or calculate it if you are unsure.

Punches are limited in compressive stress to 300,000 psi or less - 250,000psi used for safety and good punch life.

A good formula to know is Sc = (T x Ss X L) / A

Where; Sc is compressive stress in the punch

Ss is shear strength of material being punched

T is thickness of material being punched

A is cross sectional area of punch

L is length of cut (circumference of hole being punched)

Shear strength of some common materials is:
(based on about 80% of ultimate tensile strength)

Aluminum 6061-T6 29,000 psi

A36 steel 60,000 psi

Corten steel 64,000 psi

cold rolled steel C1018 60,000 psi

C1050 hot rolled steel 70,000 psi

316 stainless steel 70,000 psi

304 stainless steel 70,000 psi

Have fun but be careful and keep safety in mind! This stuff can hurt ya' !

Frank