Cutting a groove into metal

[theundermount]

hey guys, so what I have going on is a 2x2 metal bar that I'm required to "groove" on one side, currently I'm achieving this my making cuts with a grinder and then filing it out afterwards. my question is I'm looking to do this repetitively a lot of times and looking for some other ideas on how I can do this as quickly and easily as possible. I do not have a mill and this work is done remotely from my work truck, I do have access to a drill press, grinders and other stuff like that. here is a sketch of what I'm trying to do

any help is much appreciated thanks so much

 

[darkzero]

Re: Cutting a grove into metal

I'm assuming 2" x 2" solid bar? If yes & the radius size is close to a drill bit size, if the surfaces are pretty flat on the bar, clamp 2 of them together. Secure in drill press, center drill then drill the hole. That will give you 2 pieces done in one shot. If it's not solid but square tubing, use a hole saw.

 

[theundermount]

Re: Cutting a grove into metal

yes solid bar! thanks this is a great idea, if clamped tightly the drill bit shouldn't walk on me I assume

 

[joe49]

Re: Cutting a grove into metal

Anytime you need more than 1 piece make a jig/fixture. This will make set up repeatable and quicker. Add in future need makes it even more worth while.

 

[darkzero]

Re: Cutting a grove into metal

Yup hopefully not. Spot drilling is the key. I normally use spot drills before drilling a hole but if you use a center drill it will start the hole deeper than a spotting drill. Center & spotting drills are short & stout so they won't wander much when starting a hole. That will give you a fighting chance for a straighter hole as drill bits will tend to follow an existing hole.

 

[danielbuck]

Re: Cutting a grove into metal

(edit) nevermind, mis-read your post

 

[sberry]

Re: Cutting a grove into metal

How good does it have to be. Does it need to be machine tool quality or something a guy could do with a 4 1/2 grinder? I did a little job yesterday, some general cuts but the first instinct was to jig it up and then with a little care cut it with vertical bandsaw hand fed.

 

[Muckin_Slusher]

Re: Cutting a grove into metal

how long are these bars?

table saw with a steel demon diablo blade, even two blades stacked like a dado set

Does the bottom of the groove have to have a radius?

I wonder how a router table would stand up to a ball nose end mill...

 

[Ralphxj]

Re: Cutting a grove into metal

How long is the grove? How many do you have to do? Steel? Aluminum? You could build a jig that holds a die grinder at the correct position and guides it over the bar to cut/grind the groove.

 

[matt_i]

Re: Cutting a grove into metal

What is the dimension of the slot (assuming you did 2 back-to-back as Darkzero suggested) what diameter drill bit would you use?

An annular cutter is a possibility for one at a time but I wouldn't count on that sub 1/2" dia.

 

[theundermount]

Re: Cutting a grove into metal

How good does it have to be. Does it need to be machine tool quality or something a guy could do with a 4 1/2 grinder? I did a little job yesterday, some general cuts but the first instinct was to jig it up and then with a little care cut it with vertical bandsaw hand fed.

doesn't have to be laser precise, these are solid iron rods for fire hydrants, the slot is needed for a break away coupling that slips over it and is held in place by a 1/2in pin that rests in the slot, right now I do use a grinder but would rather have a jig of sorts to be able to slot it on a drill press

I'm definitely going to do some tests with clamping two rods together and hopefully I get a nice groove that way,

 

[theundermount]

Re: Cutting a grove into metal

how long are these bars?

table saw with a steel demon diablo blade, even two blades stacked like a dado set

Does the bottom of the groove have to have a radius?

I wonder how a router table would stand up to a ball nose end mill...

the rods are quite long, approx 5 ft in length and I wouldn't be able to carry a table saw with me, but it sounds like a good idea if I were to be in shop though

 

[theundermount]

Re: Cutting a grove into metal

How long is the grove? How many do you have to do? Steel? Aluminum? You could build a jig that holds a die grinder at the correct position and guides it over the bar to cut/grind the groove.

rod is solid steel, I like the idea of something I could guide over the rod quickly almost like a radial arm saw of sorts but with a small die grinder

 

[metlmunchr]

Re: Cutting a grove into metal

A basic fact of metalworking is that a drill will remove metal faster than any other cutting tool.

The first answer was the best answer you'll get.

Just use the shortest flute length that will reach thru the material, and use 135* split point drills. Both will contribute to the stiffness of the drill and minimize any tendency for the drill the walk off center.

 

[joe49]

Re: Cutting a grove into metal

Picture of actual piece? In place also.

 

[theundermount]

Re: Cutting a grove into metal

A basic fact of metalworking is that a drill will remove metal faster than any other cutting tool.

The first answer was the best answer you'll get.

Just use the shortest flute length that will reach thru the material, and use 135* split point drills. Both will contribute to the stiffness of the drill and minimize any tendency for the drill the walk off center.

thanks, I'm back to work Monday so I am definitely going to work on setting something up on the drill press

 

[theundermount]

Re: Cutting a grove into metal

Picture of actual piece? In place also.

I'm back to work Monday I will snap a couple pics of the pieces

 

[Muckin_Slusher]

Oh, so the groove is only two inches long (perpendicular to the length of the bars...)

I was picturing the groove along the length of the bar, so didnt get how a drill bit could help as it would need to be 5 feet long...

Sounds to me like handbombing it with an angle grinder is the ticket.

 

[Highland]

What I've done is cut or score a line across both pieces with a hack saw, portable band saw or even a cut off blade in a die grinder. Then when you clamp the two pieces together face to face the grooves become a pilot hole. Helps to keep the bit from wandering off track.

Obviously the straighter and more uniform the groove the better.

 

[American Locomotive]

I like the clamping of the bars together and drilling them on a drill press. The trick to making that work is making sure you clamp everything TIGHT. Clamp the bars together tight, clamp the bars to the drill press tight.

An irwin quik-grip won't work. You'll need a good 'ol c-clamp.

 

[theundermount]

here are some pictures I took from work

first is the bar with the groove I need to make, second shows how it lines up in the coupler and how the pin slides in to retain the rod and coupler together

 

[matt_i]

Just another idea...Pferd and possibly others make a flap disc with the sandpaper wrapped around the rim of the disc for dressing inside corners without shredding a standard flap disc. Saw one in stock at Menards.

I haven't used one but it seems like it might be a good tool if you have to make these one at a time without the benefit of the drill press..

https://www.zoro.com/pferd-flap-dis...dbNm41A9Ug6gojyrY24aAvHbEALw_wcB&gclsrc=aw.ds