Welding Plate Hole Layout

[yukon_rose]

I have a 12" by 12" by 1/2" mild steel plate. I want to turn it into a small welding plate. I have quite a large collection of 3/8-16 studs and other goodies for my mill so I'm going to drill and tap the plate in that size.

I was thinking that I would drill every inch.

I don't weld very often so I'm mostly guessing here.

Questions:
1) Is a 1 inch hole spacing a good choice?
2) Should the holes all be lined up or should I offset every other row by 1/2"?

Gary

 

[Firstram]

A 2 inch grid would be more than enough.

 

[finsruskw]

How Ya gonna keep the welding splatter out of the unused holes?

 

[francist]

If you’re thing about using the strap clamps / toe clamps from your milling machine setup it might make sense to drill the hole pattern based on the adjustment range on the clamps. If you have a range of, say, 1” on a toe clamp before the clamping becomes ineffective then 1” spacing may be enough. But if you only have 3/4” before your clamp starts to look goofy then you may want a tighter spacing or consider offsetting every second row to try to alleviate dead zones.

Either way you do it though, there will something that won’t fit as you want and you’ll wish for another hole just in between the ones you already have regardless of what spacing you choose.

-frank

 

[Nutfarmer]

With 12 x12 you can reach most anywhere on the plate with just c clamps.

 

[yukon_rose]

How Ya gonna keep the welding splatter out of the unused holes?

Spatter is minimal since I only do Oxy-Acetylene stuff. But I will keep a spare tap handy.

Gary

 

[yukon_rose]

With 12 x12 you can reach most anywhere on the plate with just c clamps.

That's true. But I find using C-Clamps to be awkward and difficult when I'm trying for specific angles and lengths.

Gary

 

[yukon_rose]

Either way you do it though, there will something that won’t fit as you want and you’ll wish for another hole just in between the ones you already have regardless of what spacing you choose.

That has been my experience as well. With that in mind, it sounds like you recommend offsetting every other row of holes.

Gary

 

[francist]

I wasn’t auguring for the offset specifically, it’s just one way to get a hole spacing closer together without really peppering the plate. There’s also no rule that says everything has to constant density across the whole plate — I have a small fixture plate I use extensively for my shaper and horizontal milling machine. I kept finding that I always seemed to want another hole or two just off from centre so finally I just ran another two rows up the middle offset between the ones I already had. Problem solved.