Holes for Cat 1 pins

[scott_vt]

Thanks for the help. I am needing to enlarge a 5/16" hole to 7/8" so the hole saw would pose some problems. Also there is no way to get the plates off and onto my drill press so I will need to go slow with a hand held. I will keep an eye on HF to see if they go on sale soon.

Good Afternoon Eric,
You should be able to use a 5/16" drill as a pilot for your 7/8" hole saw I believe.

 

[studor]

I know the step drill is designed for thinner materials but it works very well in a hand held drill enlarging holes -- there is one at HF that is 7/8" as part of as set of two. I have those step drills and have used them to enlarge holes in 1/2" plate by going halfway from each side I think they would work better than a hole saw in material that thick and they will stay centred even in a hand held drill -- JMHO
regards

 

[Skyco]

Quote:
Originally Posted by Eric_Phillips
Thanks for the help. I am needing to enlarge a 5/16" hole to 7/8" so the hole saw would pose some problems. Also there is no way to get the plates off and onto my drill press so I will need to go slow with a hand held. I will keep an eye on HF to see if they go on sale soon.

Good Afternoon Eric,
You should be able to use a 5/16" drill as a pilot for your 7/8" hole saw I believe.
__________________
scotty


Most hole saws have a 1/4" pilot bit, if you can find a 5/16" bit with the 1/4" shank to put into the hole saw you'd be in good shape.

 

[scott_vt]

scotty


Most hole saws have a 1/4" pilot bit, if you can find a 5/16" bit with the 1/4" shank to put into the hole saw you'd be in good shape.

Good Evenin Skyco,
Agreed ! I meant to mention that you would need a 1/4" shank 5/16" bit, sorry about that !

 

[J_J]

I am trying to modify a post driver to attach to my 3 PH. I need to drill some 7/8" holes in 1" thick plate for the lift pins. Where do you guys find 7/8" twist bits to drill these holes or do you use some other method?

You could drill three or four times, up sizing the bit each time, but seems like an awful lot of work.

Can you show a picture of what you trying to do.

If you are wanting to use the 7/8 lifting pins with threads on it, you could cut off the threaded part and weld the pin to your post driver. Will save a lot of work.

Those step bits were never designed for anything thicker than sheet metal.


http://www.tractorsupply.com/webapp...45|14351|33767?listingPage=true&Special=false

Do you have access to one of those magnetic base drill's like the ones made by Milwaukee Co.

 

[sal64]

you can get a good 7/8 drill from msc industrial supply but thet are expensive wount be easy drilling with hand drill has attendence to chatter at start step drills desined for sheet metal i think to thick for hole saw step up to 1/2 then 5/8 3/4 then 7/8 cutting oil or tapping oil witch is black oil .

 

[kcprecision]

Ok you will have to step drill it. I would go 3/8 than by 1/8s untill you reach 7/8. If you have a small drill make the steps smaller maybe 1/16s.

One time I had to mount a new gear box on a brushhog. The new gear box mounting bolt holes required new holes to be drilled for 3/4 inch by the time I got through my wrists were so sore.

One more thing that may help you is lay a small piece of cloth maybe 4X4 across the hole and drill right through it keeping cutting oil on the cloth. It does help keep the drill from hanging up.

 

[George2615]

Harbor Freight has been said. That's where I bought a set of Silver & Deming reduced shank bits. I just used mine to drill a 1" hole through 3/8" steel. I started small with a 1/4" then just kept stepping up until I got to 1". Used plenty of spray lube to keep bits cool and a 1/2" low rpm drill.

 

[DanD78]

Drilling the hole out in steps can cause the bit to grab because it will want to suck in to the steel you are trying to drill. Find your self a good 1/2" drill with two handles so you can get a good grip. If you use a quality drill bit you should be able to drill the hole out with the pilot hole you already have. Another option is a bridge reamer in a hand drill. They are great for aligning and expanding holes plus they don't grab. I have found them on ebay dirt cheep. The hole saw will probably make an over sized hole. Use black cutting oil no matter what you are cutting with but any oil is better than none.

Dan

 

[Skyco]

Harbor Freight has been said. That's where I bought a set of Silver & Deming reduced shank bits. I just used mine to drill a 1" hole through 3/8" steel. I started small with a 1/4" then just kept stepping up until I got to 1". Used plenty of spray lube to keep bits cool and a 1/2" low rpm drill.

I have a set of those and they've been surpisingly good. Seem to be good metal and hold up well.

JJ mentioned the magnetic drills- sweet machines but big bucks, maybe you can rent one.

I still favor the hole saw unless I am using a drill press or magnetic drill.

Are these holes for the threaded end of the pins or the pivot end? I wouldn't worry too much about fit on the threaded end, or really on the pivot end either unless you'll have a lot of cycle time or alignment is critical, which seems unlikely on a tractor implement.