Need to drill a hole...

[HiTechTed]

Guys, I need to drill a 1 1/8" hole in 4 pieces of 3/8" thick mild steel. I don't have a plasma cutter or a torch...all I have is a good drill press.

What would you use to do this job with given my lack of equipment? I've looked around here and there are no bits that large for sale anywhere that I've seen, but would a step drill do it? I have drilled up to 3/4" holes around here but I've never had to do one this size and I was wondering what would be best to use in my situation.

Thanks!

 

[Egon]

Hole saw??

 

[Grateful11]

A good quality holesaw will do it in dril press.

 

[BHD]

ENCO and MSC sells bits that large, I would step drill drill a 1/2" go to 3/4" and so on untill I got the size I wanted,

Enco - Guaranteed Lowest Prices on Machinery, Tools and Shop Supplies

MSC Industrial Supply Co. | Find Power Tools, Hand Tools, Machine Tools & More

 

[moored4]

Guys, I need to drill a 1 1/8" hole in 4 pieces of 3/8" thick mild steel. I don't have a plasma cutter or a torch...all I have is a good drill press.

What would you use to do this job with given my lack of equipment? I've looked around here and there are no bits that large for sale anywhere that I've seen, but would a step drill do it? I have drilled up to 3/4" holes around here but I've never had to do one this size and I was wondering what would be best to use in my situation.

Thanks!

If your thinking of doing this with a torch then I will assum it dosent have to be percise! A whole saw will work but if you need a tight tolarance ( metal to metal fit) then take it to a fab shop and have them do it. :thumbsup:

 

[SPYDERLK]

ENCO and MSC sells bits that large, I would step drill drill a 1/2" go to 3/4" and so on untill I got the size I wanted,

Enco - Guaranteed Lowest Prices on Machinery, Tools and Shop Supplies

MSC Industrial Supply Co. | Find Power Tools, Hand Tools, Machine Tools & More

Stepping is a good strategy to be able to drill a big hole without a good drillpress. With a good press it isnt needed tho and can destabilize the process. Grabbing and orbital chatter can be a big issue. The drill point pushing against solid metal is most stable. For drilling 1-1/8 in a good press Id go max 1/4" for the pilot hole ... plenty of lube and speed under 100rpm.
larry

 

[sldva00]

I've drilled 7/8" holes through 3/8" steel using bi-metal hole saw with no problems. Like SPYDERLK said, go slow and use lubricating oil. A 1-1/8" hole wouldn't be a probem.


Milwaukee 1-1/8 in. Bi-Metal Hole Saw 49-56-9663

 

[HiTechTed]

I've never used a hole saw for anything other than wood and never even considered it for this job. I've just never ran into a situation where I needed to put a hole this size in metal so my knowledge of it is a bit limited! So then I just need a bi-metal hole saw with an arbor and bit and I'm good, right?

 

[SPYDERLK]

Frequent and diligent chip clearing. Do a hole in a piece of scrap hardwood and use it to guide the start cut.
larry

 

[Grateful11]

Stepping is a good strategy to be able to drill a big hole without a good drillpress. With a good press it isnt needed tho and can destabilize the process. Grabbing and orbital chatter can be a big issue. The drill point pushing against solid metal is most stable. For drilling 1-1/8 in a good press Id go max 1/4" for the pilot hole ... plenty of lube and speed under 100rpm.
larry

It sounds like you're a fairly experienced Machinist. I've got almost 30 years in myself. Your suggestion is spot on, a pilot drill slightly larger than the web of the drill :thumbsup: