Drilling..

[spieagle]

Hello Friends,
I have to perforate a 4 feet*8 feet SS sheet of thickness 8mm. The hole shape that is to be perforated is round hole of dia 8mm and pitch of 18 mm. my perforating press has the capability of perforating upto 4mm only therefore i have decided to drill the holes throught the sheet.
Does anyone have any idea about what sort of drilling machine should i use fixed in a jig that slids through a distance equal to pitch and drill holes. What about a magnet base drill.
Kindly tell if this is possible or i am just killing my time over it.
Thanking you.

 

[eromlignod]

If it's austenitic (300-series) stainless, then a magnetic drill won't even stick. See if you can find a machine shop that has a large radial jig-borer or an NC mill that can handle that large a sheet. Other options are laser or plasma cutting, depending on how accurate your hole diameters have to be.

Don
Kansas City

 

[alejandroillini]

machining would be insanely expensive as eromlignod said a laser is your best bet If you don't have a laser find a shop that does if you are in the states try

http://www.accuratemetalfab.com

they are very good and have those capabilities. They have done perf on their laser before. If you are not in the states and based on the meteric measurement chances are good that your not international shipping is expensive so try to find someone local with a laser.
I hope that was helpful

 

[spieagle]

thanks eromlignod and alegandroilini for replying, every bit of information is helpfull. Actually i am from INDIA and i dont have laser or plasma cutting machines for me the only option is drilling , i have to find out the way in which it can be done easily.

 

[JDana]

perforate the 4mm and drill out to 8mm? depending on tolerances you may be able to just drill by hand.

 

[alejandroillini]

JDana I understand why you are saying to punch the hole in half the diameter. but I don't think punching holes that are half the material thickness is a good idea you might just end with a bigger head ache and a bunch of expensive scrap. it is doable but never recommend to punch less than a material tickness espesially that many holes out of a material in which the tool is only a little bit harder than the material you are punching

 

[spieagle]

well alejandroilini is correct punching less than a material thickness will damage the die, punch guide everything, but there is a solution of one thing in jdana's reply, i was wondering how would i be able to take the centres of the hole exactly equal to the pitch(18mm) on the sheet but this can be done with the help of die assembly and the machine we will not be punching 4mm but only taking centres.

 

[unclesyd]

Before the advent of tubesheet drilling machines we drilled all our tubesheets and baffles on a Radial Arm Drill Press.

We made plywood templates either one half or full size details and then used a center punch to transfer the locations on the templates to the blanks. We would then pilot/center drill each position then drill at half size and then full size.

 

[JDana]

Of course 4mm is too small to pierce 8mm thickness, I admit to unintentionally ignoring that fact with my reply.

If it ends up helping with locating, at least it helped some.