Drilling 3/8" holes in 1-1/4" square bar stock??

[finsruskw]

Newbie question here....
I need to drill 24 holes (2 each) in 12 pieces of 1.25" square bar 3.5" long.
Whats the best way to do this?
Space and drill all the holes before cutting to length, or drill each piece after cutting to length using a vise stop and seting up the DRO for proper spacing?
What speed and feed to use?
Pilot hole or not?
Drill bit or end mill?

I want to do this right and not ruin any bits or cutters in the process as there may be more to do in the future.

Thanks Guys!
I am sure having a ball w/my Jet now it is up and running w/the DRO installed.

 

[machPete99]

It depends a bit on the tolerances of the holes to each other and ends of the (cut) bars, but...
I would tend to cut all pieces to length (slightly oversize), and mill one end on each.
Set a stop in the vice and mill 2nd end if required (to desired final length) on each.
Use stop to drill first hole on each piece (first with center drill, then with main drill) on each.
Use stop to drill second hole on each piece.

 

[MrWhoopee]

Part length tolerance?
Hole size tolerance?
Hole spacing tolerance?
Hole location tolerance (relative to part)?

 

[T Bredehoft]

Spot drill each hole with a spot drill

Form a habit of using a spot drill (a rather short drill bit with a broad point,) so that the point of the 3/8 (or whatever) drill finds the center (not the sides) of the initial hole.

Some of us call what is actually a screw machine drill (short drill, short flutes, broad point) a 'spot' drill.

 

[finsruskw]

It depends a bit on the tolerances of the holes to each other and ends of the (cut) bars, but...
I would tend to cut all pieces to length (slightly oversize), and mill one end on each.
Set a stop in the vice and mill 2nd end if required (to desired final length) on each.
Use stop to drill first hole on each piece (first with center drill, then with main drill) on each.
Use stop to drill second hole on each piece.

Thanks Pete,
So just go in with the 3/8 bit after a spot?
Kind of what I was thinking.
Saw finish on ends is OK but I will mill them to clean them up.
Want them to look nice because this may turn into a run of more.
Is a 1/2" end mill big enough to side mill the ends or should I go lareger?
3/4" is the biggest I have for now
Here are the pieces I did the other day and they both sold overnight.!

 

[tq60]

Cut to length plus finishing room. (If saw cut is not square then mill square.

Mark with scribe (pair of calipers works well)

Center punch with good sharp point.

Place in vice and support extended end and have hole in open.

Center drill on mark and with a good sharp 3/8 drill bit drill the hole and move on.

Sent from my SAMSUNG-SM-G930A using Tapatalk

 

[rwm]

This have been debated before, but it is acceptable in these here parts to use a center drill if you don't have a spot drill. I have both and I have not seen much of a difference.
Robert

 

[middle.road]

Newbie question here....
I need to drill 24 holes (2 each) in 12 pieces of 1.25" square bar 3.5" long.
Whats the best way to do this?
Space and drill all the holes before cutting to length, or drill each piece after cutting to length using a vise stop and seting up the DRO for proper spacing?
What speed and feed to use?
Pilot hole or not?
Drill bit or end mill?

I want to do this right and not ruin any bits or cutters in the process as there may be more to do in the future.

Thanks Guys!
I am sure having a ball w/my Jet now it is up and running w/the DRO installed.

Material?
If steel then:
If the tooling budget allows it, try to get your hands on a Ø5/8" or Ø3/4" carbide endmill. You've got (24) 'ends' to face off.
I've got one with the tip chipped off that I use for facing steel. Quite a bit quicker and easier than HSS.
Try to use a good quality Ø1/2" drill bit. Again because it qty (24) holes...

 

[MrWhoopee]

Since saw cut ends are ok, disc or belt sand the ends (and chamfers). Looks good if done carefully and much faster than milling. If hole spacing & size are not tightly controlled, use a stub length 3/8 drill at about 850 rpm without center-drill.

 

[finsruskw]

Just using mild hot roll.
Nothing fancy, just brackets for hydraulic cylinder mounts on a 42" snow blade.
Stubby drill bits I have, also spot drill set to 1/2"
Thanks for the replies guys!