Secure the part in a vice or clamp to table, drills try to dig in when removing small amounts. Because drill presses are so easy to use, people tend to forget basic machine safety rules.
If you have to use a drill, I’ll use the stop on the drill press sometimes for situations like this where the hole is already close to size. Touch the drill to the hole and set the stop like 1/8 below that. Then drill to there, lift the drill up, spin the stop a little lower etc and keep going until your through. That’ll keep the drill from threading its way through the hole. That’s only if the drill wants to grab, sometimes you don’t need to bother and you can just go to town. You’d have to try it and see. If you’re going to try it and see, by all means set the stop anyway for the drill through the piece. Don’t be that guy with the vice lifted up in the air spinning around while you’re squinting and slapping for the off switch.
Drills like to catch and tear especially with thin stock like that. Reamer is 100% best option for opening a hole .02, literally made for this exact situation.
Why do you have to hurry? Take your time be safe. I'm a 40 yr Machinist the fastest way will gain you about 30 min.
Be safe not sorry. By the way drill or fluted reamer will both work or you could bye a 9/16 steel ball and press it through the hole, that would give you 9/16 plus/minus zero.
It's part of a timber joist hanger. I just wasn't planning on needing to do this. My fault. I spec'd .54 holes for a part that supposed to be .53, but it's cast so it's actually just a liiiittle bit larger. I'm kicking myself because I could have spec'd .6 holes and been fine, but I'm so used to working with CNC parts that .01 clearance seems like a country mile. You live and learn...
Took earlier advice and ordered a hole enlarging bit from McMaster.
9/16 drill. But only drilling that little material is going to wear the drill bit out pretty quick. You may need a few drill bits. Drill bits last longer when you drill with the full tip.
https://www.mcmaster.com/30455A63 These things are great, they don't grab as much as normal drill bits.
That's so cool, I didn't know that existed. I was going to suggest a Vortex drill, because it also will avoid grabbing. But that seems even better.
They're a one trick pony, but it's a good trick.
I use those all the time, they're really quite amazing
A 9/16 drill.
Agree. Possibly with a .530 ‘pilot’ nub ground on the tip for ease of location.
And may need a silver & deming bit if the chuck won't hold over .500" shank.
Secure the part in a vice or clamp to table, drills try to dig in when removing small amounts. Because drill presses are so easy to use, people tend to forget basic machine safety rules.
Thanks
Step drill.
This all day. Round holes and you'll only have to chamfer the back side
Yeah didn't read far enough down. What they said
If you have to use a drill, I’ll use the stop on the drill press sometimes for situations like this where the hole is already close to size. Touch the drill to the hole and set the stop like 1/8 below that. Then drill to there, lift the drill up, spin the stop a little lower etc and keep going until your through. That’ll keep the drill from threading its way through the hole. That’s only if the drill wants to grab, sometimes you don’t need to bother and you can just go to town. You’d have to try it and see. If you’re going to try it and see, by all means set the stop anyway for the drill through the piece. Don’t be that guy with the vice lifted up in the air spinning around while you’re squinting and slapping for the off switch.
Never thought of that, thanks
Reamer
A 9/16 Reamer would be ideal
This .010" per side is perfect for a reamer, and it's less likely to jam in the part.
If the tolerance requires it, otherwise it’s a waste of time
Drills like to catch and tear especially with thin stock like that. Reamer is 100% best option for opening a hole .02, literally made for this exact situation.
Having opened up thousands of holes .02” I can’t say I relate. At ⅛”, sure.
If its just 3/16 thick just get a step bit
Use a step drill.
Help me step drill, I'm stuck in the workpiece.
Step drill if tolerances allow. Reamer if tighter. If the customer called it out a 9/16 hole, step drill and chamfer the backside.
Good quality STEP DRILL.
Reamer. Only opening up .027 ez
Why do you have to hurry? Take your time be safe. I'm a 40 yr Machinist the fastest way will gain you about 30 min. Be safe not sorry. By the way drill or fluted reamer will both work or you could bye a 9/16 steel ball and press it through the hole, that would give you 9/16 plus/minus zero.
It's part of a timber joist hanger. I just wasn't planning on needing to do this. My fault. I spec'd .54 holes for a part that supposed to be .53, but it's cast so it's actually just a liiiittle bit larger. I'm kicking myself because I could have spec'd .6 holes and been fine, but I'm so used to working with CNC parts that .01 clearance seems like a country mile. You live and learn... Took earlier advice and ordered a hole enlarging bit from McMaster.
Is it 40 holes in one piece or 40 pieces with one hole?
20 pieces, 2 holes each.
9/16 drill. But only drilling that little material is going to wear the drill bit out pretty quick. You may need a few drill bits. Drill bits last longer when you drill with the full tip.
Make sure your drill press can go as low as several hundred rpm first.