Cutting 4” hole in stainless?

[rwdenney]

Holex appears to make a variety of cutters, including an annular cutter like this:

HSS core drill Depth of cut 30 mm, TiAlN, ⌀ D_C: 50mm | Hoffmann Group

Buy HSS core drill Depth of cut 30 mm, TiAlN, ⌀ DC: 50mm at the Hoffmann Group eShop: ✓ Personal advice ✓ Exclusive top products

www.hoffmann-group.com

They also make a hole saw, which I don’t think would be nearly as good:

Carbide hole saw flat, ⌀ D_C: 50mm | Hoffmann Group

Buy Carbide hole saw flat, ⌀ DC: 50mm at the Hoffmann Group eShop: ✓ Personal advice ✓ Exclusive top products

www.hoffmann-group.com

Oh I see Val-Cut is a trepanning cutter. That seems tough in stainless.

What grade stainless?
How many holes?
What tolerance?

Only the hole saw is sized large enough for a 4" hole.

I think the only alternative is either a CNC with a high-speed carbide mill or a boring bar in a manual mill, unless you can mount the workpiece on a lathe fixture plate and bore it there.

Rick "pics would help" Denney

 

[rwdenney]

Wow, been a while since I seen one of those. I have one that’s called a Bore master Jr that has carbide inserts. Made in Germany. Have never used it. Still in the box

Personally, I can't imagine those are stiff enough to cut thick, tough material. I've only ever seen these recommended for thin, soft metals or wood.

Rick "who also has one somewhere" Denney

 

[jwmelvin]

Only the hole saw is sized large enough for a 4" hole.

Oops! Thanks. For some reason I was looking at 50mm diameter. A 4” annular cutter would be quite a thing.

 

[rwdenney]

4" Carbide Tipped Hole Cutter, 1" Depth of Cut - Mutual Screw & Supply

www.mutualscrew.com

It has a 3/8" shank. Do you think that would be stiff enough with a 4" cutting diameter in 3/4"-thick stainless? I've always though of these as being used for sheet metal, like for drain holes in stainless steel sinks and vent holes in stainless steel range hoods.

Rick "fearful it would wobble all over the place in heavy material until it broke" Denney

 

[MikeInOr]

It has a 3/8" shank. Do you think that would be stiff enough with a 4" cutting diameter in 3/4"-thick stainless? I've always though of these as being used for sheet metal, like for drain holes in stainless steel sinks and vent holes in stainless steel range hoods.

Rick "fearful it would wobble all over the place in heavy material until it broke" Denney

I have used similar cutters of MUCH smaller diameters in thick aluminum with good results. I honestly have no idea if that cutter would work well for your project. I think your concerns are valid concerns.

I have seen shanks made to adapt annular cutters for use on mills. Allowing the use of most any annular cutter on a mill.

Amazon.com

How many 4" holes do you need to cut? Why is is plasma not an option?

 

[Smithdoor]

What would be the best way to machine cut a 4” hole in 3/4” stainless? Plasma is not an option. I’ve cut two holes with 3/8 end mill on rotary table but taking to long. I have a Val Cut but it’s breaking bits. I’ve read about a Holex brand with two cutters, they are pricey. Has anyone used the Holex on stainless? Any other recommendations on cutting this part?

I have hole saws they go about 1 ½" . I typically cut haft on one side and flip over and finish the hole.

A mag drill great but if 300 serious the need to clap a steel plate for mag drill to hold on to for drilling. Also works on aluminum too.

Dave

 

[taltexan]

I have used similar cutters of MUCH smaller diameters in thick aluminum with good results. I honestly have no idea if that cutter would work well for your project. I think your concerns are valid concerns.

I have seen shanks made to adapt annular cutters for use on mills. Allowing the use of most any annular cutter on a mill.

Amazon.com

How many 4" holes do you need to cut? Why is is plasma not an option?

40 holes. Plasma deforms the part. Tried it but customer said no! I ordered a carbide cutter from Mutual be here tomorrow. I’ll report if it’s going to work. I’m drilling and turning them on the Lathe now but an hour and a half per. Broke 3 inserts already….316L is a booger to work.

 

[twraska]

40 holes. Plasma deforms the part. Tried it but customer said no! I ordered a carbide cutter from Mutual be here tomorrow. I’ll report if it’s going to work. I’m drilling and turning them on the Lathe now but an hour and a half per. Broke 3 inserts already….316L is a booger to work.

What about a water jet and then a boring head to size.

 

[Pevehouse]

Personally, I can't imagine those are stiff enough to cut thick, tough material. I've only ever seen these recommended for thin, soft metals or wood.

Rick "who also has one somewhere" Denney

I agree, and they could only cut that in a mill

 

[tq60]

A carbide toothed hole saw in a vertical mill with back gear, slow rpm, high cutting pressure.

We drilled 3.5 inch diameter through 1.25 plate with a bimetal hole saw.

The plate was a disk drom the scrap yard, used lathe in back gear and vfd slow, maybe 60 rpm.

Braced the TS chuck to keep from rotating.

Plenty of oil, cutter stayed cool, slug got hot.

Use hole saw just undersized, then finish with boring bar in same setup to keep center.

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